 MacKay was the New Democratic Party's candidate for the division of Wolseley in the 1973 provincial election.On election night, official results showed that he had received the same number of votes as Liberal Party leader Izzy Asper.Jim Maloway, the returning officer, cast a tiebreaking vote for MacKay and declared him as the elected member; a subsequent recount, however, determined that Asper actually won by four votes.