So much of the political dysfunction in our country comes from the structures built in to accommodate slavery at the founding and the subsequent south v north poitical alignments that have followed the civil war, which are just an extension of that divide. Racism and division are the roots of so much. The current state of the Republican party has a lot to do with the Dixiecrats abandoning the Democrats (good riddance!) following the civil rights act.
I've been reading Ezra Klein's "why we are polarized" right now. He is making a compelling case that while there are some policy differences, much of it has to do with the conversion to having politics as part of a cultural identity and the innate human tendency to act strongly against "others" with a different identity (even down to utterly pointless divisions, as shown in numerous research experiments). Hence, the "owning the libs" approach taken by Trump is very effective once a person has identified as anything but a "lib", and why those groups are so immune to change in support regardless of what happens in the factual world. It is worth noting that there is some truth on the other side with TDS, though the same conclusion could also be reached in that case based on a cold read of Trump's pandemic response, etc. .... but i digress. In this context, there is no downside among supporters for breaking rules/norms/precedents to advance your own group, especially if it is bad for the other party. I expect McConnell sees nothing but upside in ramming a SCOTUS appointment through, when viewed through this lens. There is literally nothing in his history I can think of that says he would take any other action.
I honestly don't know how to get around the politics of identity. It is completely anathema to the concept of democracy, which requires deliberation and compromise to function. Party over country is dyfunctional in a democracy no matter the political origin.