Actually, they have a central idea that explains their hatred of the ACA, namely, that government is part of the problem, not part of a solution. They simply cannot abide any program that is run by the government - especially if it is successful. This is similar to their constant harping on entitlements as if they are the scourge of mankind. Their ideal budget cuts would decimate social security, medicare, etc.
They see, and state explicitly, that these programs are huge steps down the road to unbridled socialism and that is to be feared above all else. And that is what the GOP sells:fear. Fear of socialism, fear of blacks, fear of immigrants, ....
it's fear all the way down.
That also partially explains Dump. He sells fear constantly - no wonder the rank-and-file Republican approves of him. He confirms their deep fears and tells them they are right to be afraid.
*dismounts soapbox*