As best as anyone can tell, the child migrant crisis is playing perfectly into the hands of conservatives in congress — it's making Obama look bad while pushing Democrats off their immigration reform message. Then along comes Ted Cruz to ruin it all with a plan reported by Manu Raju and Burgess Everett to link any new funding to deal with the situation to deporting DREAMers — kids who came to the US years ago, grew up here, and are now being protected from deportation by Obama administration executive action.

Catherine Frazier, a spokesperson for Cruz, describes ending the deferred action plan as his "top priority."

Of course one senator taking an eccentric stand needn't have major political implications. But this is essentially how last fall's government shutdown got started. Cruz floated the idea that Republicans should refuse to fund the government unless the White House agreed to repeal Obamacare. Most Republican members of congress thought that was unworkable and politically unwise. But once the idea gained traction in the conservative media, nobody wanted to take the RINO stand of breaking with Cruz out of political timidity. Next thing you know the whole caucus was stampeding off the cliff.

Obama's deferred action (and its legislative predecessor, the DREAM Act) has always polled well. There's likely nothing Democrats would rather do than shift the conversation onto that terrain, while simultaneously allowing them to argue that it's Republicans who are distracting attention from the crisis of the moment.

But Cruz isn't necessarily interested in what's best for his caucus. He's interested in what's best for driving Cruz's influence inside the caucus. And that means finding new fights to pick beyond the ones the party leadership is interested in.