The RW is all about litmus tests*. For a lot of RW folks, hating Hillary is one of the badges of membership. No badge, no entry. Mr. Plumber is reassuring his voters that he does have that all-important badge.
* Actually litmus tests are the hallmark of extremists of all stripes. Witness the Bernie Bros who couldn't / didn't vote for Hillary last time because she didn't pass the socialist wacko litmus test. Look where that got them. But they did retain their all important doctrinal purity.
Some of the hard core LW is now trying to drag Biden so far out that instead of sensible Rs voting for Biden (voting against Trump really), those sensible Rs will choose to abstain. Which is much less effective at defeating Trump than a vote for Biden would be.
Meantime the LW wackos are threatening that they’ll be the ones staying home if Biden doesn’t go wacko LW.
The big difference between the LW & RW wacko factions today is the LWs are WAG ~10% of their party and the RWs are demonstrably ~40% of theirs.