Robert Costa explains why there are so many Republicans in Congress committed to an effort that is certain to fail:

And so many of these members now live in the conservative world of talk radio and tea party conventions and Fox News invitations. And so the conservative strategy of the moment, no matter how unrealistic it might be, catches fire. The members begin to believe they can achieve things in divided government that most objective observers would believe is impossible [bold mine-DL]. Leaders are dealing with these expectations that wouldn’t exist in a normal environment.

Costa’s explanation seems to be the only way to account for Republican behavior that otherwise makes no sense. Picking an extremely unpopular fight that they are sure to lose doesn’t serve the party’s interests, and it doesn’t even seem to serve the longer-term interests of individual members. The trouble is that the Republicans most eager to have this fight may believe that they can prevail somehow, and they seem to be encouraged in this belief because they are relying on the same sources of misinformation that have served them so poorly in the past.

It is as if no one learned anything from the experience of the party-wide delusion that Romney was going to win the election. Some Republicans are making all of the same mistakes that they made when they ignored all of the evidence suggesting that the GOP was likely to lose in 2012. Most of the time, the echo chamber hurts conservatives and Republicans by making them oblivious to inconvenient facts and ideas, but in this case it is leading them to believe in an alternate political reality with its own set of rules. In that alternative reality, a pointless, self-defeating effort becomes a clever political strategy, and obnoxious and politically toxic tactics are treated as normal and appropriate.