Sure not every democrat was like Larry McDonald but there is a reason Reagan was able to have a defacto trifecta in the first two years of both of his terms and that’s because there was like 40-45ish southern conservative democrats who would go along with him on most of his agenda .
It’s the same reason FDR was unable to pass much of his agenda post 1938 and the same is true for Truman and the fair deal and LBJ post 1966. It’s cause conservatives had defacto control of the house from 1938-1946 , 1950-1952, 1954-1958 , 1966-1970 , 1981-83, 1985-87 despite democrats having a majority in all these cases. So the conservative coalition had a majority 22 of those 62 years and republicans had actual majorities for 4 so you could say that liberals had a majority for 36 years while conservatives had for 26 which is still a advantage to liberals but not as profound as 58 vs 4
It certainly wasn’t all southern democrats but there were a good deal that went along with republicans much of the time
