He was re-elected by 940 votes in the 1977 election, and by 340 votes in the 1981 election. He crossed the floor to join the Progressive Conservative Party in 1984, complaining that the Liberal Party was going nowhere under David Peterson's leadership. McEwen had been known in the Liberal caucus as a difficult figure, and rarely attended meetings. Some believe he wanted to ensure his own re-election by changing sides. The Progressive Conservatives had planned to nominate Sally Barnes, a prominent aide to Premier William Davis, to challenge him in the next election.