It's simple. The problem is with the other 434 Congressmen and the other 98 Senators. Theirs are good.

Actually the problem, and it was created by both parties is the gerrymandering of congressional districts. These almost guarantee the incumbent will be not only relected, but that the incumbent has the freedom to move, or maybe they were already there, to the far left or far right.

Congress works best when the 2 or more sides have to come together and compromise. Many people don't know this, but Ronald Reagan and Tip O'Neill were actually good friends. They would meet in private, hammer out a compromise that each side could live with and got it passed. Now it is all "my/our way or the highway".