For most of the population, the notion of non-consensual sex is considered worse than the notion of consensual sex. These days, we're trying to even teach young adults to engage others opt-in rather than opt-out (e.g. get a yes first).

But yes, this is very recent, with challenges to the criminality of wife-rape as recent as the 1970s (and the presumption that abuse within families was their business and not that of the state or of law-enforcement -- that changed in the 1990s!)

So yes, there are folks like Matt Walsh and Tucker Carlson who are literally pro-rape (that is, sex assault should be legal in some circumstances) and pro-child-marriage (Tennessee is trying to create a higher tier of marriage that gets more benefits, excludes gay couples but allows for marrying girl children.) So yes, some Republicans may hold more contempt for Clinton's consensual proclivities than for Trump's non-consensual ones.

But more likely it's because to Republicans, loyalty is more important than principal, and anything can be condoned if someone marches in lockstep and salutes snappily for the transnational white power movement.