My sister and brother-in-law supported Trump... not like 'MAGA' levels, but they were pretty invested. Their kids are 6 and 3 so maybe not the best case study - I don't think they talked about much of anything political with them. I also know their kids don't watch much news TV so it'd be interesting to hear from parents of like... kids between the ages of like 8-13 or something.
That said, I think the answer might be straightforward. People make excuses for politicians all the time so I imagine a lot of the "reconciliation" is much the same as the way people reconcile these things themselves.