In Trump's meeting with Obama, they spent quite some time on ACA. Afterward, Trump told reporters he quite liked the preexisting condition coverage and keeping young adults on family policies. (Of course everybody likes those.)

He said maybe we need to modify ACA rather than repeal it! Not Republican at all!

It basically comes down to letting people with preexisting conditions die or not. That is the bottom line. Insurance WAS cheaper when you could buy policies that quit as soon as you got sick. You want real insurance, it is going to cost real money.

There simply isn't that much wriggle room for changing ACA. To make it much cheaper, you have to screw somebody. It may be doctors, may be drug companies, may be insurance companies, may be patients. Take your pick.

It has VERY little to do with being Republican or Democratic. Maybe we just rebrand it "TrumpCare" with a few superficial changes? Lower subsidies? (But people who elected Trump mostly complain about the cost, which is the exact opposite of lower subsidies.)