As for the legal challenges, Trump will be abandoned by the Republican party hierarchy and donors, who will have a choice between going down with his ship in a blaze of self-destruction, or jumping off and looking ahead to 2024.
Never under-estimate politicians' self-preservation.
He'll certainly have the overall popular vote by some margin.
I think the Dems have a much better ground game than in 2016 (as evidenced in the mid-terms).
Trump, of course, will claim victory at some point on the day and it will get very messy over the next few weeks (journalists ordering bullet-proof vests apparently).
I expect the lame duck, tail end of Trump's White House will be an absolute wrecking ball.