 In the lead-up to the dismissal of the Whitlam Government in 1975, he strongly defended the power of the Senate to block supply.However, he believed that Governor-General John Kerr had acted unconstitutionally in dismissing the prime minister, and said that he would have challenged the decision in the High Court if he had been in Whitlam's position.McMahon believed that those responsible for the "loans affair" – including Whitlam and several of his ministers – had acted illegally and should be prosecuted for their involvement.