What's the most important thing to Republicans? Cutting taxes on the wealthy. The wealthy are the ones who want it, and the wealthy have managed to convince the middle class Republican voter that cutting taxes on the wealthy will create jobs for them - all nonsense of course, but political beliefs are hard to change, and decades of propaganda by the Oligarchy have had their effect. The failed attempt by the Republicans to kill Obamacare was really not much more than a tax cut for the wealthy, camouflaged with distracting rhetoric.
It's an ideology called Reaganomics - cut taxes to spur the economy. But it doesn't work. Reagan cut taxes and the economy grew (after he raised taxes again a few times). Clinton raised taxes and the economy grew even more. W cut taxes and the economy flat-lined. Reaganomics is just a dogmatic belief that doesn't work, but the duped by the Oligarchy Republican common voter hasn't figured that out yet.
Dogma, dogma, dogma - the killer of democracy.