In 2016 I originally supported Rand Paul. I think he'd lose the rust belt (WI would be very close) but win CO, NV, and NH simply because most of the people who voted for Gary Johnson would go to Paul*, who would also perform slightly better in the West anyway. I also think Paul's position on criminal justice reform and non-interventionalism would help him among nonwhites and voters under 40.
This could also be Rubio's map, but he'd be vulnerable in OH/IA.
* I hate the Nate Silver trope that 3rd party votes hurt Hillary more than Trump, as someone who was a (small l) libertarian for many years (but not anymore) and familiar with what most GJ voters thought, Libs in general roundly despised HRC even if they weren't fans of DT by any stretch. If GJ wasn't an option, I could see 75% plus of his votes going to Trump and the remainder split between Clinton and McMullin (who also wouldn't have been a factor if anyone but Trump was the nominee.
Ted Cruz: too conservative for CO/NV/NH, little rust belt appeal. Does well in Fl and AZ.
Jeb Bush: wins NV/NH, loses CO, ME-2 and VA, 269-269.
Walker:
Kasich:
