Probably Rubio up by 3-7 over President Clinton. After 12 years of Dem rule people will be ready for change. Rubio will have become a bit more seasoned by then.
Only if she turns out to actually be a bad president. People don't just want change regardless after many years of the same party, they tend to want it when things aren't getting done and/or the public's views have changed
(such as 18-29 year olds swinging heavily away from liberalism)If she somehow gets a lot of things done and presides over a good economy, she will win reelection. If Republicans continue acting like the whites-only party and don't moderate their platform, then they could lose in 2024 as well.