How Trump has reshaped the ACA
The Affordable Care Act used a carrot-and-stick approach to get healthy people to sign up for coverage. The stick is the individual mandate and the penalty for going uninsured; the carrot is a system of subsidies to help people afford their premiums. Under Republicans' watch, the stick is getting a lot weaker while the carrot is looking more and more delicious.
What's happening: We're ending up in a place where the poorest consumers can get even cheaper coverage than the ACA intended, especially if they choose less comprehensive care, while wealthier consumers increasingly don't have much incentive to get covered at all. Those trends will only grow more pronounced if Republicans successfully repeal the individual mandate in their tax bill, leaving the law with only its carrot, and no stick.