The 1966 United States Senate elections were elections on November 8, 1966, for the United States Senate which occurred midway through the second (and only full) term of President Lyndon B. Johnson. The 33 seats of Class 2 were contested in regular elections. Special elections were also held to fill vacancies. With divisions in the Democratic base over the Vietnam War, and with the traditional mid-term advantage of the party not holding the presidency, the Republicans took three Democratic seats, thereby breaking Democrats' 2/3rds supermajority. Despite Republican gains, the balance remained overwhelmingly in favor of the Democrats, who retained a 64–36 majority. Democrats were further reduced to 63–37, following the death of Robert F. Kennedy in June 1968.

Quick Facts 35 of the 100 seats in the United States Senate 51 seats needed for a majority, Majority party ...

1966 United States Senate elections

← 1964 November 8, 1966 1968 →
35 of the 100 seats in the United States Senate 51 seats needed for a majority
Majority party Minority party   Leader Mike Mansfield Everett Dirksen Party Democratic Republican Leader since January 3, 1961 January 3, 1959 Leader's seat Montana Illinois Seats before 67 33 Seats after 64 36 Seat change 3 3 Popular vote 12,971,141[1] 13,654,168[1] Percentage 48.1% 50.6% Seats up 20 15 Races won 17 18
Results of the elections:      Democratic hold      Republican gain      Republican hold      No election Rectangular inset (S. C. and Va.): both seats up for election
Majority Leader before election Mike Mansfield Democratic Elected Majority Leader Mike Mansfield Democratic

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These were also the first elections held after the enactment of the Voting Rights Act of 1965. Upon Edward Brooke's election in Massachusetts, he became the first African-American U.S. Senator elected after the end of Reconstruction and the first-ever popularly elected, as Reconstruction ended before the passage of the Seventeenth Amendment to the United States Constitution. As of 2024, this is the most recent Senate election cycle in which no House incumbents were elected to the Senate and the last time any state elected different parties to each Senate seat in a double barrel election.

More information Parties, Total ...

Parties					Total
		Democratic	Republican	Other
Last elections (1964)		68	32	0	100
Before these elections		67	33	0	100
Not up		47	18	0	65
Up		20	15	—	35
	Class 2 (1960→1966)	18	15	—	33
	Special: Class 1	1	0	—	1
	Special: Class 3	1	0	—	1
Incumbent retired		1	2	—	3
	Held by same party	0	2	—	2
	Replaced by other party	1 Democrat replaced by 1 Republican		—	1
	Result	0	3	0	3
Incumbent ran		19	13	—	32
	Won re-election	15	13	—	28
	Lost re-election	1 Democrat replaced by 1 Republican		—	1
	Lost renomination, but held by same party	2	0	—	2
	Lost renomination, and party lost	1 Democrat replaced by 1 Republican		—	1
	Result	17	15	0	32
Total elected		17	18	0	35
Net gain/loss		3	3		3
Nationwide vote		12,358,323	13,169,332	271,245	25,798,900
	Share	48.10%	50.64%	1.26%	100%
Result		64	36	0	100

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Source: Clerk of the U.S. House of Representatives^[1]

Nine races had a margin of victory under 10%:

There is no tipping point state, as the Arkansas, Georgia, and Louisiana races were all unopposed.

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1966 United States Senate election in Alabama

← 1960 November 8, 1966 1972 →

Nominee John Sparkman John Grenier Party Democratic Republican Popular vote 482,138 313,018 Percentage 60.07% 39.00%

County results Sparkman:      50–60%      60–70%      70–80% Grenier:      60-70%

U.S. senator before election John Sparkman Democratic Elected U.S. Senator John Sparkman Democratic

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Incumbent Democrat John Sparkman was easily reelected to a fourth full term. Republican challenger John Grenier received 39% of the vote, the best result that a challenger to Sparkman had ever received to that date, presaging the rise of the Republican party in Alabama after decades of Democratic dominance.

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1966 United States Senate election in Alaska

← 1960 November 8, 1966 1970 (special) →

Nominee Bob Bartlett Lee McKinley Party Democratic Republican Popular vote 49,289 15,961 Percentage 75.54% 24.46%

Results by state house district Bartlett:      60–70%      70–80%      80–90%

U.S. senator before election Bob Bartlett Democratic Elected U.S. Senator Bob Bartlett Democratic

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Incumbent Democrat Bob Bartlett was reelected to his third (a second full) term in a landslide, defeating Republican candidate Lee McKinley in a rematch of the 1960 election.

Incumbent Democrat John L. McClellan was reelected unopposed to a fifth term in office.

This article needs additional citations for verification. (June 2020)

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1966 United States Senate election in Colorado

← 1960 November 8, 1966 1972 →

Nominee Gordon Allott Roy Romer Party Republican Democratic Popular vote 368,307 266,198 Percentage 58.02% 41.93%

County results Allott:      50–60%      60–70%      70–80% Romer:      50–60%      60–70%

U.S. senator before election Gordon Allott Republican Elected U.S. senator Gordon Allott Republican

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Republican incumbent Gordon Allott was reelected to a third term, defeating Democratic state senator and future governor Roy Romer.

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Delaware election

← 1960 1972 →

Nominee J. Caleb Boggs James M. Tunnell Jr. Party Republican Democratic Popular vote 97,268 67,263 Percentage 59.12% 40.88%

County Results Boggs:      50-60%      60-70%

U.S. senator before election J. Caleb Boggs Republican Elected U.S. Senator J. Caleb Boggs Republican

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Republican incumbent J. Caleb Boggs won reelection to a second term over Democratic candidate James M. Tunnell Jr., whose father had served in the Senate in the 1940s.

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1966 Democratic Senate primary election in Georgia

← 1960 September 14, 1966 1972 →

Nominee Richard Russell Jr. Harry Hyde Party Democratic Democratic Popular vote 596,209 61,922 Percentage 90.59% 9.41%

County results Russell:      60–70%      70–80%      80–90%      >90%

U.S. senator before election Richard Russell Jr. Democratic Elected U.S. Senator Richard Russell Jr. Democratic

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Democratic incumbent Richard Russell Jr. was reelected unopposed to a sixth full term (and seventh overall.)

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Idaho election

← 1962 (special) 1972 →

Nominee Len Jordan Ralph Harding Party Republican Democratic Popular vote 139,819 112,637 Percentage 55.38% 44.62%

County Results Jordan:      50–60%      60–70% Harding:      50–60%      60–70%      70–80%

U.S. senator before election Leonard B. Jordan Republican Elected U.S. Senator Leonard B. Jordan Republican

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Republican incumbent Leonard B. Jordan won reelection a full term, having previously served out the unexpired term of the late Henry Dworshak. He defeated Democratic Congressman Ralph R. Harding.

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1966 United States Senate election in Illinois

← 1960 November 8, 1966 1972 →
Turnout	71.56%
Nominee Charles Percy Paul Douglas Party Republican Democratic Popular vote 2,100,449 1,678,147 Percentage 54.95% 43.90%
County results Percy:      50-60%      60-70%      70-80% Douglas:      50–60%
U.S. senator before election Paul Douglas Democratic Elected U.S. Senator Charles H. Percy Republican

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Incumbent Democrat Paul Douglas, seeking a fourth term in the United States Senate, faced off against Republican Charles H. Percy, a businessman and the 1964 Republican nominee for Governor of Illinois. Also running was Robert Sabonjian (I), Mayor of Waukegan. A competitive election ensued, featuring campaign appearances by former Vice-President Richard M. Nixon on behalf of Percy.^[2] Ultimately, Percy ended up defeating Senator Douglas by a fairly wide margin, allowing him to win what would be the first of three terms in the Senate.

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1966 United States Senate election in Iowa

← 1960 November 8, 1966 1972 →

Nominee Jack Miller E.B. Smith Party Republican Democratic Popular vote 522,339 324,114 Percentage 60.92% 37.80%

County results Miller:      50-60%      60-70%      70-80%      80-90%

U.S. senator before election Jack Miller Republican Elected U.S. Senator Jack Miller Republican

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Republican incumbent Jack Miller was reelected to a second term, defeating Democrat Elbert B. Smith, who had previously run for the state's other Senate seat in 1962.

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1966 United States Senate election in Kansas

← 1962 (special) November 8, 1966 1972 →

Nominee James B. Pearson James Floyd Breeding Party Republican Democratic Popular vote 350,077 303,223 Percentage 52.15% 45.17%

County results Pearson:      40–50%      50–60%      60–70% Breeding:      40–50%      50–60%

U.S. senator before election James B. Pearson Republican Elected U.S. senator James B. Pearson Republican

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Incumbent Republican James B. Pearson won reelection to a full term, having previously served out the unexpired term of Andrew Frank Schoeppel following Schoeppel's death. He defeated Democratic Congressman James Floyd Breeding.

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1966 United States Senate election in Kentucky

← 1960 November 8, 1966 1972 →

Nominee John Sherman Cooper John Y. Brown Sr. Party Republican Democratic Popular vote 483,805 266,079 Percentage 64.52% 35.48%

County results Cooper:      50-60%      60-70%      70-80%      80–90% Brown:      50–60%      60–70%

U.S. senator before election John Sherman Cooper Republican Elected U.S. Senator John Sherman Cooper Republican

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Republican incumbent John Sherman Cooper won reelection over Democrat John Y. Brown Sr., an attorney and former Congressman.

Incumbent Democrat Allen J. Ellender was elected unopposed to a sixth term.

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1966 United States Senate election in Maine

← 1960 November 8, 1966 1972 →

Nominee Margaret Chase Smith Elmer H. Violette Party Republican Democratic Popular vote 188,291 131,136 Percentage 58.93% 41.04%

County results Smith:      50–60%      60–70%      70–80% Violette:      50–60%

U.S. senator before election Margaret Chase Smith Republican Elected U.S. senator Margaret Chase Smith Republican

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Republican incumbent Margaret Chase Smith won reelection to a fourth term over Democrat Elmer H. Violette, a state legislator and future judge of the Maine Supreme Judicial Court.

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1966 United States Senate election in Massachusetts

← 1960 November 8, 1966 1972 →

Nominee Edward Brooke Endicott Peabody Party Republican Democratic Popular vote 1,213,473 774,761 Percentage 60.68% 38.74%

County results Municipality results Brooke   40–50%   50–60%   60–70%   70–80%   80–90%   90–100% Peabody   40–50%   50–60%   60–70%

U.S. senator before election Leverett Saltonstall Republican Elected U.S. Senator Edward Brooke Republican

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Republican State Attorney General Edward Brooke defeated his challengers. Republican incumbent, Leverett Saltonstall, was retiring after serving for 22 years. Brooke was the first black U.S. senator elected since Reconstruction.

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1966 United States Senate election in Michigan

← 1960 November 8, 1966 1972 →

Nominee Robert P. Griffin G. Mennen Williams Party Republican Democratic Popular vote 1,363,530 1,069,484 Percentage 55.90% 43.85%

County results Griffin:      50-60%      60-70%      70-80% Williams:      40–50%      50–60%

U.S. senator before election Robert P. Griffin Republican Elected U.S. Senator Robert P. Griffin Republican

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Republican incumbent Robert P. Griffin won reelection to a full term, having initially been appointed to the seat following the death of Patrick V. McNamara six months earlier. He defeated Democratic former Governor G. Mennen Williams.

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1966 United States Senate election in Minnesota

← 1960 November 8, 1966 1972 →

Nominee Walter Mondale Robert Forsythe Party Democratic (DFL) Republican Popular vote 685,840 574,868 Percentage 53.94% 45.21%

County results Mondale:      40–50%      50–60%      60–70%      70–80% Forsythe:      40–50%      50–60%      60–70%

U.S. senator before election Walter Mondale Democratic (DFL) Elected U.S. Senator Walter Mondale Democratic (DFL)

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Incumbent Democratic U.S. senator Walter Mondale, who had originally been appointed in 1964 to replace Hubert Humphrey after Humphrey was elected Vice President of the United States, defeated Republican challenger Robert A. Forsythe, to win a full term.

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Mississippi election

← 1960 1972 →

Nominee James O. Eastland Prentiss Walker Party Democratic Republican Popular vote 258,248 105,150 Percentage 65.56% 26.70%   Nominee Clifton R. Whitley Party Mississippi Freedom Democratic Popular vote 30,502 Percentage 7.74%

County Result Eastland:      40-50%      50-60%      60-70%      70-80%      80-90% Walker:      40-50%      50-60%      60-70%

U.S. senator before election James O. Eastland Democratic Elected U.S. senator James O. Eastland Democratic

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Incumbent James Eastland, who first entered the Senate in 1941, faced the opposition of Prentiss Walker, the state's first Republican congressman since Reconstruction.^[9][10]

Walker, who voted against the Civil Rights Act of 1964, ran on the right of Eastland and solely focused on the white vote, accusing him of not being hard enough in opposing integration and being friendly with President Johnson, accusations to which Eastland partisans opposed the fact Walker nominated a black constituent, Marvell Lang, to the Air Force Academy.^[11][12][13] He proudly announced he went to a meeting of the Americans for the Preservation of the White Race, a Ku Klux Klan front, enabling Eastland to proudly announce he was opposed by both the Klan and the AFL-CIO.^[13]

Eastland cast the civil rights movement with the tar of Communism and Black Power and raised the bloody shirt of Reconstruction against the candidacy of Walker.^[12] He was supported by segregationists Tom Brady, George Wallace and Leander Perez.^[13]

Most of the White voters stayed with Eastland, and Walker ironically won African-Americans in southwestern Mississippi who wanted to cast a protest vote against Eastland.^[9]

Years later, Wirt Yerger, the chairman of the Mississippi Republican Party in the 1960s, said that Walker's decision to relinquish his House seat after one term for the vagaries of a Senate race against Eastland was "very devastating" to the growth of the GOP in Mississippi.^[14]

Reverend Clifton Whitley also ran for the Mississippi Freedom Democratic Party.^[12][15] A sore-loser law was invoked against Whitley, who ran in the Democratic primary, and he only won one week before the election, thereby preventing to enter any serious campaign or fundraising.^[13]

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1966 United States Senate election in Montana

← 1960 November 8, 1966 1972 →

Nominee Lee Metcalf Tim Babcock Party Democratic Republican Popular vote 138,166 121,697 Percentage 53.17% 46.83%

County results Metcalf:      50–60%      60–70%      70–80% Babcock:      50–60%      60–70%

U.S. senator before election Lee Metcalf Democratic Elected U.S. Senator Lee Metcalf Democratic

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Incumbent United States senator Lee Metcalf, who was first elected to the Senate in 1960, ran for re-election. He won the Democratic primary uncontested, and moved on to the general election, where he was opposed by Tim Babcock, the Republican nominee and the Governor of Montana. Though the race remained close, Metcalf was able to expand on his 1960 margin of victory, and defeated Babcock to win a second term.

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1966 United States Senate election in Nebraska

← 1960 November 8, 1966 1972 →

Nominee Carl Curtis Frank B. Morrison Party Republican Democratic Popular vote 296,116 187,950 Percentage 61.04% 38.75%

County results Curtis:      50–60%      60–70%      70–80%      80–90% Morrison:      50–60%

U.S. senator before election Carl Curtis Republican Elected U.S. Senator Carl Curtis Republican

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The incumbent Republican Carl Curtis was re-elected to a third term, defeating outgoing Democratic Governor Frank B. Morrison.

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1966 United States Senate election in New Hampshire

← 1962 (special) November 8, 1966 1972 →

Nominee Thomas J. McIntyre Harrison R. Thyng Party Democratic Republican Popular vote 123,888 105,241 Percentage 54.03% 45.90%

County results McIntyre:      50–60%      60–70% Thyng:      50–60%      70–80%

U.S. senator before election Thomas J. McIntyre Democratic Elected U.S. Senator Thomas J. McIntyre Democratic

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Incumbent Democrat Thomas J. McIntyre was reelected to a full term, having previously won a 1962 special election to serve out the unexpired term of the late Styles Bridges. He defeated U.S. Air Force General Harrison Thyng.

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New Jersey election

← 1960 1972 →

Nominee Clifford P. Case Warren W. Wilentz Party Republican Democratic Popular vote 1,278,843 788,021 Percentage 60.02% 36.98%

County results Case:      50-60%      60-70% Wilentz:      50–60%

U.S. senator before election Clifford P. Case Republican Elected U.S. Senator Clifford P. Case Republican

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Republican incumbent Clifford P. Case was reelected to a third term in a landslide over Democratic Middlesex County Attorney Warren W. Wilentz.

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1966 United States Senate election in New Mexico

← 1960 November 8, 1966 1972 →

Nominee Clinton Anderson Anderson Carter Party Democratic Republican Popular vote 137,205 120,988 Percentage 53.14% 46.86%

County results Anderson:      50–60%      60–70% Carter:      50–60%      60–70%

U.S. senator before election Clinton Anderson Democratic Elected U.S. Senator Clinton Anderson Democratic

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Democratic incumbent Clinton Anderson was reelected to a fourth term over Republican candidate Anderson Carter.

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1966 United States Senate election in North Carolina

← 1960 November 8, 1966 1972 →

Nominee B. Everett Jordan John Shallcross Party Democratic Republican Popular vote 501,440 400,502 Percentage 55.59% 44.40%

County results Everett:      50–60%      60–70%      70–80%      80–90% Shallcross:      50–60%      60–70%

U.S. senator before election B. Everett Jordan Democratic Elected U.S. Senator B. Everett Jordan Democratic

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Incumbent Democrat B. Everett Jordan was reelected to a second full term (and third overall), defeating Republican challenger John Shallcross.