The McCain Republicans are Assistant Democrats.
How soon we forget that Juan McLame gave cover to his fellow Democrats in the Keating Five scandal...
The McCainiacs don't care if they give up some US Senate seats or the governorship for a while - just as long as they can get rid of MAGA and get back to the good old days of milking the Uniparty System for their own benefit.
Some may do that, others will not, those are the ones you need to reach, the way I see it is, Republicans are in no position to write off any potential voter, the McCain voters voted Republican for a long time, they may not be MAGA Republicans, but a vote is a vote, and Republicans need every one of them, what you don’t do is tell all McCain voters to get the hell out of the Republican Party, that only alienates them and the Republican gets defeated.