1948: Unsure
1952: Unsure
1956: Unsure
1960: John Diefenbaker
1964: John Diefenbaker
1968: Robert Stanfield
1972: Robert Stanfield
1976: Unsure
1980: Joe Clark
1984: Brian Mulroney
1988: Brian Mulroney
1992: Brian Mulroney
1996: Unsure between Jean Charest and Preston Manning
2000: Unsure between Joe Clark and Stockwell Day
2004: Stephen Harper
2008: Unsure
2012: Unsure
2016: Rona Ambrose
2020: Erin O'Toole
Preston Manning and Stockwell Day were similar to US Republicans. You would absolutely not like them
Also, Harper was more liberal than McCain or Romney so you'd probably go with Harper against them too