Remember what is at stake for the GOP
The GOP is no longer even trying to hide the fact that it is going to cheat to win the election. They are now facing an existential crisis:
* A massive turnout against Trump will not only shift the Presidency and the Senate into Democratic hands, but it will also result in the loss of several state legislatures and GOP friendly governors. This means that they will lose the ability to gerrymander in favor of Republican politicians for the next decade. Without that, the archconservative GOP will go extinct. Romney might be able to resuscitate a much more moderate GOP from the embers, but the vast majority of people now in power will lose out.
* There's been a lot of corruption, and it will be investigated if he does lose. This will implicate Trump and his cronies and nepotistic appointees, but it will also likely reach into the Senate as well. Given a choice between staying in power by betraying the country or going to jail, they will happily tear the Constitution to shreds.