Rubio-mentum is real. Are Jeb Bush and Chris Christie going to play spoiler?

Rubio’s unexpectedly strong performance in Iowa last night gave the Republican establishment new hope. His respectable third-place finish, nipping at Donald Trump’s heels, was evidence that there is a constituency for a Barack Obama-like candidate who can plausibly play the dual roles of outsider and insider. As Michael Brendan Dougherty observed, “The conservative and national media began openly cheering for him last night.”

But this all means Rubio might be running into a hail of fire. A central quirk of the Republican race is that the establishment candidates have been reluctant to attack the front-runners, instead training their sights on each other, in the style of a Mexican standoff, in the hopes that the last bloodied survivor will square off against Trump or Ted Cruz. Jeb Bush’s super PAC has spent $30 million in ads attacking Rubio alone, and as Rubio heads into New Hampshire with the wind in his sails, he can expect more of the same, not only from Bush, but also from the likes of Chris Christie.

All this plays, of course, into the hands of Trump and Cruz. It raises the possibility that the establishment’s main enemy is not the two renegades, but itself.