He became the SNP's organiser in the 1930s when the party was still headed by John MacCormick, but he resisted MacCormick's later attempts to change the SNP from supporting a policy of full Scottish independence to supporting a modicum of Home Rule. MacCormick would leave the SNP in 1942 from which point McIntyre became the party's leading figure.
McIntyre served as Party President until 1980 after his stint as leader. He died 2 February 1998.