Following the retirement of
Alister McMullin, Cormack was elected
President of the Senate on 17 August 1971, defeating Labor's
Justin O'Byrne by 31 votes to 26. He had earlier defeated
Reg Withers to become the Coalition's nominee for the position, despite Withers having the support of Prime Minister
William McMahon. As president, Cormack was known as a defender of
parliamentary sovereignty over the executive. He strongly supported the expansion of the
committee system, which was a relatively recent innovation, and believed the Senate should function "largely as a committee chamber" rather than simply mirroring the House of Representatives. Fearing it was "degenerating into a propaganda forum", Cormack introduced new conventions for
question time, allowing government ministers to terminate questions without notice and refusing to allow questions to be directed to assistant ministers. He also allowed ministers to cut short debate on a bill by simply moving that it be considered "urgent". Cormack played a role in the "
Gair Affair" of 1974, which had implications for the
Whitlam government's ability to pass legislation through the Senate. He refused to accept
Vince Gair's purported resignation letter, instead judging it to be ambiguous and allowing the Senate to debate whether it should be accepted. It was expected that the vote for the presidency would be tied at 30 votes each for Cormack and the Labor nominee Justin O'Byrne, with the result determined by drawing lots. However, at least one Coalition senator voted for O'Byrne, who defeated Cormack by 31 votes to 29. ==Later years==