I would only stop short of blaming him for the divisiveness. It was already there. He is only guilty of exploiting the divisiveness, which has traditionally only been a power source for the Left, but he found a way to harness it for his own version of conservative-leaning progressivism.
At this point, it just seems like we are in an extended process of selecting the type of post-republic government we will have (assuming there will be only one, which is a big assumption). But, this country has certainly gone through divisive times in the past, so it may well weather this one, and the future may look back on these times like we look back on the LA riots and the late 60's.
But, all bets are off if Biden packs the Court and the Senate. I think that would indicate that we are in the beginning phase of a break-up of the United States.