If this is a re-alignment election; why?

[ProgressiveModerate]

Say the polls are right - non-white voters across the board swing 20%+ right, age polarization vanishes or possibly even inverts, and so on

Why would this election specifically be such a large re-aligning election? Both the candidates are the same form the last election. Neither’s messaging has changed significantly. There hasn’t been some major recession or world war. What would be the acclimate for this sort of re-alignment?

This is personally part of the reason I don’t really buy polls right now - they suggests a massive re-alignment which I just don’t see justified. Yes I buy non-white voters could swing right and seniors could swing a tad left, but by nowhere near the magnitude polls suggest. In general most of the “re-alignment” type results in polls seem to favor Trump, which is part of the reason I believe polls are currently underestimating Biden.