They have really deviated to the extremist side of politics and turned off the American voter. They will now lose the house. If anybody should be investigated by the committee on un american activities , it's the teas party.
A couple of influences are working here. First, the effect of Citizens United is now being felt across the legislative branch of the federal government. Specifically, it is the Koch brothers that are throwing hundreds of millions of dollars to influence gerrymandering, voter suppression, and other issues at the state level.
They are now throwing tons of money at House members that are buying into their dogma about how THEY think America should be run.
The other influence is to eliminate the power of the Presidency. The GOP can never again win the Presidency, so they are going to control the legislature and retake power given to the Presidency in the early Nixon years.