I lack
@Greenbeard's telepathic powers so I can't comment what is in Trump's mind, other than he said. He already abolished the powergrab mandate penaltax during his last presidency.
As for
@Citizen, my memory is certainly better than your ability to click a link.
Given that Trump will need 60 Senators to pass anything, Trump is as unlikely to completely repeal Obamacare in 2025 as he was in 2017. Voters know this. Which blows up the whole "insanity" thing. If people know Trump can't do it, then there's no more danger in voting for that than any politician's promises that won't be kept.
But even if Trump does somehow manage to repeal Obamacare, something else will replace it. To pretend otherwise is self-delusion or demagoguing, take your pick.