Both Clinton and Trump have their dedicated base. Both have baggage. The only thing that has changed is that Trump now has a proven track record for us to judge him by. That can cut either way, depending on your political leaning. HC has been able to do a lot of "I told you so", which plays to her base, but I don't think that's enough to change the balance in a re-match.
When you cut through all the trash talk and rhetoric, I think many traditional Republicans feel an uneasy alliance with Trump. While he is a daily embarrassment to the office, he's on their side. To them, power is more important than personality. Although they might rather see a more "presidential" Republican in office, they support Mr Trump.
The Democrats would be foolish to try a Trump-Clinton rematch. No matter how much power she has within the party, Clinton still has a lot of credibility problems. So does Trump, but he's a better con artist than her.
Ultimately, this country needs a moderate president who can bring both sides together. I don't see that happening with either Trump or Clinton.