Premiership

All three political parties in Queensland had changed their leaders by 1989 — in addition to the Nationals, the Liberals were now led by Angus Innes and Labor by Wayne Goss. Cooper had a dimmer view of the proposed Fitzgerald reforms than Ahern and put off their implementation. Although the legislation establishing the Criminal Justice Commission (CJC) was passed under Cooper, he would later have an adversarial relationship with the Commission itself. Although Cooper's elevation did have some effect within rural electorates, the Nationals' overall fortunes continued to tail off.

Cooper waited as long as he could to call an election, finally doing so for 2 December. The Nationals campaigned on traditional focuses: law and order, social conservatism, and attacks on the federal Labor government. The Nationals produced a number of controversial advertisements, one of which alleged that the Labor Opposition's plan to decriminalise homosexuality would lead to a flood of gays from southern states moving to Queensland.^[6] These advertisements were satirised by Labor ads depicting Cooper as a wild-eyed reactionary.

In the election, the Nationals were heavily defeated, suffering the worst defeat of a sitting government in Queensland. This was mainly due to a massive Labor wave that swept through Brisbane; Labor took all but five of the capital's 36 seats. However, Cooper was not blamed for the debacle—which was widely seen as a vote against Bjelke-Petersen—and stayed on as Leader of the Opposition.

Post-premiership

In 1991, allegations were made in The Courier-Mail that a large number of Queensland parliamentarians from all parties had abused their travel entitlements (the "travel rorts affair"). The CJC began an investigation, and although the names of those under investigation were suppressed, it became obvious through indirect published hints that one of them was Cooper. On 9 December Cooper announced that he was under investigation for the funding of a trip to Hamilton Island with his wife, refunded the cost of the trip, and stood down as National Party leader. This was widely seen as a tactical move aimed at shaming senior members of the government such as Terry Mackenroth. Cooper was succeeded by Rob Borbidge. The CJC subsequently cleared Cooper of impropriety.

Following the redistribution, which followed legislation designed to rid Queensland's electoral system of malapportionment in favour of rural areas, Cooper transferred to Crows Nest at the 1992 election. He returned to the Nationals' front bench in November of that year as Shadow Minister for Police. In February 1996, when Borbidge formed a minority government after winning a closely fought by-election in Mundingburra, Cooper became Minister for Police, Corrective Services, and Racing.

Soon afterwards Cooper was named in what would become the central scandal of the Borbidge government, when it was revealed that during the Mundingburra by-election campaign, Borbidge and Cooper had signed a secret Memorandum of Understanding with the Queensland Police Union guaranteeing the QPU the repeal of unpopular Goss government measures, the power of veto over senior police appointments, and increased police funding in return for a donation of A$20,000 to the by-election campaign. This close relationship evoked many memories of the Bjelke-Petersen era, where relations between the executive and the police service were (sometimes improperly) close. When the matter came under investigation by the CJC (the Carruthers Inquiry), Cooper led strident attacks on the body and its independence. Cooper ignored repeated Opposition calls for him to resign.

In 1998, the Coalition suffered an 11-seat swing, and Labor's Peter Beattie formed a minority government. Cooper became Shadow Minister for Primary Industries but stepped down from the front bench in December 1999. He retired from Parliament in the state election of 2001.^[1]