It makes sense. The so called Blue Dogs or moderate Democrats were decimated. The most left Democrat members from left districts are left. They are pretty bullet proof in their districts and personally are better off not making accommodations with the GOP.
Notice how the red areas have grown and the blue areas have shrunk since the last three elections. This is a sea change in American politics as more and more people are seeing the Dems for what they are. The hardcore liberal areas are becoming smaller and smaller islands in a sea of red. The conservatives have to keep educating the American people about the basics. When you talk in the language of common sense the people will respond. RINOS have other agendas and that is what causes the problems in the Republican party. Look at some of the gutsy conservative people that we have now who speak in the language of the people, not like the RINOS who are putting on a mask of conservatism.