They don't have to listen to their districts because those are so solidly Republican that they can afford to lose a number of voters and still will. These districts are that way due to a mix of gerrymandering and 'the big sort'. It's not a lot of districts, but enough to stall everything, given the tiny majority the Rs have.
One of the'problem' Reps has announced that she will run in a different (more solidly R) district next election as she'd lose the one she's now in.
The US founders built the gov't based on the Roman model: make it easy to stop, hard to start any major action (they were focused on the end of the Republic).