I'm also not sure there's a majority appetite for the Romney/Ryan brand of conservatism any longer. Republicans have to run on a populist platform to bring in more working class minorities into the party.
I think this election showed us that most Americans still don't like the politics of DJT, as the popular vote clearly shows. They also don't much care for far left Dems, which is why Biden won the primary pretty easily. Biden was definitely more center leaning than pretty much all of his campaign opponents, save may be Gabbard.
Trump has been able to rile up a certain subsect of voters that otherwise may not have voted, but let's be real, at least 80% of his supporters will likely vote Republican no matter what. Independents seem to have flocked to Biden this election. Numbers are at record highs likely due mail in ballots more than anything else. Don't discount the affect that an Irish Catholic like Ryan would have in Northeastern states, either.