Well, in all fairness to the Republican middle, we really only had a conservative party during the Regan years and the first term of the Republican House in 1994.
Before that, wasn’t Gerald Ford’s vice president Nelson Rockefeller, Left Wing Republican? Nixon wasn’t so conservative by today’s standards, and not Eisenhower, either. Hoover wasn’t (he started intervening in the economy in 1929, only making it worse). Coolidge was. I really don’t think we’ve had any before that. Maybe Jefferson.