Romney.
There's few better indicators that someone would be a good president than if they were previously a good governor. Hell, even Bill Clinton was a better president than Obama was.
Romney was a good governor? I suppose if you like gun bans, --something he and Trump have in common with each other.
Romney got cap-and-trade for CO2 in Massachusetts, something that eventually became the Regional Greenhouse Gas Agreement (RGGI), which my old state of Maryland signed onto (of course).
Be honest. Trump did not ban guns. If you really want a real gun ban, allow Biden to win again.