I already know the answer, but would McCarthy and House Republicans risk a civil war? Surely there would be immense pressure from CEOs, military, international leaders,
In the event of an electoral college tie, it would be perfectly legal for McCarthy and House Republicans to vote for their preferred candidate.
A failure to do so would rightly piss off a lot of voters.
Nobody said anything about legality. Of course it'd be perfectly legal for them to do so. It being perfectly legal, however, would by no means make it, y'know, the right thing to do, & their actively "do[ing] so would rightly piss off a lot of voters."