Trump diverted money from other defense appropriations and started building his wall. The rest of the story is available to those who want to be informed.
Trump originally said Mexico would pay for the wall.
Trump said he had a great healthcare plan. At one point, he said preexisting conditions were caused by lifestyle choices, so people with them should pay more. Later, he said he had the concept of the plan
We have Medicare because most elderly people are uninsurable in a free market.
We got the ACA because the free market would not cover preexisting conditions at standard rates unless there was a mandate requiring young and healthy people to buy in. Talking that out watered it down.
OTOH, the roll out of the tax penalties and refundable credits was so poorly conceived it almost toppled the ACA before it took root.
Republicans also did others things to sabotage the ACA, but it has survived in spite of that.
To say the old non-group free market was better before the ACA is bs. Many people in that sector were uninsured, some by choice, some due to preexisting conditions.
The coverage people could afford to get often sucked, like exclusion for pregnancy or complications of pregnancy.