This has just really been because a small group of extreme wingnuts, who were dealt a severe loss in public polling this week and also by the president not giving in to ransom. It hopefully won't continue to be a recurring theme in the upcoming years, mainly due to the extreme public backlash.
I would love more than anything for you to cite the claim that they've taken a huge hit in polling in their districts/states. I looked around, can't find one - but if you have one I would greatly appreciate. I do not think that they did, however, and no amount of popularity dip among people outside his state can stop Ted Cruz from filibustering and raising hell.
The GOP overall has the lowest ratings in polling history. Yes babbling idiots in small districts where these Tea Party folks hail from will be re-elected due to gerrymandering, but they are a small minority.
Cruz previously didn't filibuster, he didn't have the votes for that. It was a long "speech" that Reid allowed to happen, but he was never able to continue on indefinitely.
I'd be worried about the moderates who will get voted out by the public due to this issue, not the small biased districts who will continue to raise hell, and get nowhere.