The coward will.
This is a hill worthy of dying on, but Mitch and the other spineless establishment Republicans in name only will cut and run.
If one lives in a state with a contested R incumbent, inform their office in a professional manner if McConnell folds, you will simply withhold any and all support for their re election efforts and make sure 10,20,50 other individuals will be persuaded to also withhold support and vote. Flooding DC and local phone lines and e mails stating consequences of approving a rabid liberal to the SCOTUS may be what is needed to have these jellyfish evolve a spine. Also state the consequences of the Senate folding to your elected congresscritter that your support will be withheld.
Cut and run from their firm belief that Obama gets whatever he wants? or merely from one of the things they have muttered about?
It’s what Vichy collaborators do...