Elections

Massachusetts Senator Dianne Wilkerson failed to file her nomination petition with enough valid signatures to appear on the ballot in the Democratic primary during the 2006 election, but announced that she would run a write-in campaign for the Democratic nomination.^[6] Chang-Díaz announced on June 18, 2006, that she would run as a write-in candidate in the primary.^[5] Wilkerson defeated Chang-Díaz in the initial primary, but a judge ordered a recount due to write-in votes not being counted in eight precincts.^[7] Secretary of State William F. Galvin started an investigation into Boston's handling of elections due to the error.^[8] Chang-Díaz turned in enough signatures for a recount of all ten wards.^[9] The final recount determined that Wilkerson had won by 767 votes which was more than the initial 141 votes.^[10] Wilkerson won reelection in the general election.^[11]

Chang-Díaz ran against Wilkerson in the 2008 Democratic primary and defeated Wilkerson.^[12][13] A recount was conducted and maintained Chang-Díaz's victory.^[14] Wilkerson launched a write-in campaign in the general election, but withdrew after she was arrested on charges of public corruption and Chang-Díaz defeated Wilkerson and independent candidate William Theodore Leonard in the general election.^[15][16][17] She was the first Hispanic woman elected to the Massachusetts Senate.^[18]

She won reelection without opposition in the 2010, 2012, 2016, 2018, and 2020 elections.^{[19][20][21][22][23]} She defeated Republican nominee David James Wyatt in the 2014 election.^[24]

Tenure

During Chang-Díaz's tenure in the Massachusetts Senate she served as the chair of the Education committee, vice-chair of the Senate Redistricting committee, and assistant vice-chair of the Ways and Means committee.^[25][26][27] She was speculated as a possible candidate for the 2013 Boston mayoral election, but did not run and instead endorsed Marty Walsh.^[28][29] She endorsed Donald Berwick for the Democratic nomination in the 2014 gubernatorial election.^[30] She endorsed Senator Ed Markey in the Democratic primary during the 2020 United States Senate election.^[31] During the 2020 Democratic presidential primaries Chang-Díaz endorsed Senator Elizabeth Warren.^[32]

Chang-Díaz announced on June 23, 2021, that she would seek the Democratic nomination in the 2022 gubernatorial election, but ended her campaign on June 23, 2022, although she remained on the ballot.^[33][34]