At least some of what is commonly described as Republican self-abasement before Trump is actually responsiveness to GOP voters, which in a democratic republic is not entirely a bad thing. Republican voters chose Trump and keep choosing him, no matter your view on whether party leaders should have done more to persuade them otherwise. This raises questions about how to lead the party constructively as it actually is rather than as one might wish it to be.
But to acknowledge the dilemmas involved is not to say elected Republicans have grappled with these questions effectively or that there is no limit to what party loyalty can demand. As Edmund Burke said, “Your representative owes you, not his industry only, but his judgment; and he betrays, instead of serving you, if he sacrifices it to your opinion.” It is simply to recognize that it is not realistic to expect a successful political party to repudiate its own electoral base.
It is entirely possible that Trump will go down and take the rest of the party with him. That initially happened to Republicans following Watergate. But it is worth recalling that within six years of Richard Nixon’s resignation, in a far less polarized media and political climate than exists today, Ronald Reagan was elected president. The party did not end up purging all Nixon loyalists as a price for reclaiming power. “This too shall pass,” Reagan reassured Nixon on Watergate in 1973. George H.W. Bush came to favor Nixon’s resignation, but he did so relatively late.