Their rabid anti-Mormon stance was the crack that let the rest of the hate in.
There was some of that yes. However the excusing any level of liberalism was always there. Robinson and most of his disciples never failed to vote for the GOP regardless of how liberal said GOP pol was. House, Senate or President.
What there was, was a group of moderates at best that talked and talked about conservative this and partiotic that. But come election day, the ONLY day anything really matters in politics, they lined up with whatever liberal the GOP offered and as a result, they moved the conservative 'movement' left one vote at a time.
Moderates, by definition are unprincipled. Then there was the outright liberal plants besides egging them on. You see that here as well, though they are currently few. But loud.