If you added up the five key political figures at this point (Mayor Pete, Joe Biden, Bloomberg, Senator Warren, and Bernie Sanders), I would rate them in this fashion against Trump.
1. Bernie Sanders. By far, the one that would be purely capitalism versus socialism, and I would suggest that Trump might be able to hustle up forty-five states on the 'win' side.
2. Senator Warren. Virtually everything she wants to talk about....has a price-tag attached. So taxes would have to rise. On the advertising front for October, she'd make it pretty easy for Trump to get 30 to 35 states.
3. Mayor Pete. Trump would basically talk non-stop over Mayor Pete's resume. Again, I'd give Trump the call for 30 to 35 states.
4. Joe Biden. Joe has the resume, and can appeal to working-class voters. Joe's problem is age, and sometimes suggesting things that are a bit crazy. In a debate, Joe is Joe's worst nightmare. Trump would face a Hillary-like force and probably only win 30 to 32 states.
5. Finally, Bloomberg. Bloomberg would not appeal to the Bernie-socialism voters, or the Senator Warren crowd. Bloomberg's past behavior with women, and paying them off...would be dragged out. All things considered....I think Bloomberg could take Florida, and make this a 29-state win for Trump....meaning it'd be a lot closer but Trump would likely still win.