@hightor,
It appears to me you are merely speculating based on your presumptions about the behavior of large, in some cases poorly defined, groups of people. Indeed to some extent your Group identifications and your predictions are reflexive and identical.
We can all observe the emerging dilemma in the Democrat Primary involving the choice between a presumed safe Biden Candidacy and a more radical one, perhaps chosen in part based on favored left wing group identities. It appears the prospect of a Biden victory is far less certain than presumed , but still not impossible. Meanwhile none of the crowd of more radical left wing candidates has, as yet, shown much ability to withstand for long the critical examinations attendant to a campaign. There is also a danger that in their current fixation on their own issues and versions of them Democrat supporters may find there is much less public support for their favored (and generally only superficially described) programs than they imagine.
On the Republican side there are the still uncertain elements of public reactions to the Trump Presidency. Will our currently strong economic performance have its historical effect on the behavior of voters? Will the evident anxiety associated with Trump's direct engagement of long term, unresolved issues like International Trade and immigration overcome public hopes and concerns over long overdue efforts to address these longstanding issues?
The campaign rhetoric of both sides is usually simplistic and exaggerated, and that is certainly the case now. It often seems to me that the increasingly shrill Democrat rhetoric about the supposed treatment of immigrants at the border; Trump's supposed affection for tanks etc. and their continued beating of the very dead Mueller investigation horse may well persuade many that they are a dangerous and unreliable political force.
I sometimes suspect that Trump may be goading them to produce more of it.
All of these matters are very hard to quantify, and I certainly can't predict the outcomes with confidence. It appears you recognize these uncertainties as well.