Gen X (45-64) is a very weird age-based outlier on this one. I blame libertarianism.
As both bloggers remark, the clear trend is that Trump is much more highly approved by every demographic except the voters he appealed to in 2016. Three out of ten Mexicans agree, “he’s not as bad as I was expecting“.
I’d argue this is a sign he’s transitioned from one of Arthur Finklestein’s “personality” candidates to a “structural” candidate. And since Biden is also a structural candidate, typical demographic Republican vs. Democrat voting patterns would prevail (if I’m right), which indicate a very close match with Biden winning due primarily to demographic shift. That claim is based on Razib Khan’s electoral map.