That was a rough debate for Marco Rubio. He finally got that long-awaited challenge on his previous support for the “Gang of Eight” immigration-law overhaul, which he handled well enough. But any way you look at it, this puts him to the left of the field on the major animating issue of the campaign. He continually took fire from a surging Ted Cruz and a feisty Rand Paul. He spent much of the night on the defensive.

He acquitted himself adequately enough through all that, sure, but what do we really have to support the idea that this is the guy who can prevent Cruz or Donald Trump from capturing the GOP nod? To unite the factions of the party that recoil at the thought of nominating either Trump or Cruz, Rubio may well have needed a much bigger, better night than the one he had Tuesday.

And what Rubio really didn’t need was another establishmentarian like Chris Christie putting points up on the board. Part of the reason Cruz and Trump and Ben Carson have been so successful has been that the moderate vote is divided among so many candidates; the best thing that could’ve happened for the anti-insurgent effort is for a clear alternative to the Cruz/Trump emerging in the very near future, and that sure didn’t happen Tuesday night…

So what if the Great Establishment Hope, the insurgent-killer so many of us were waiting for, never emerges? It’s kind of hard to process the Republican nomination coming down to a choice between the Senate’s least-popular showboat and a New York billionaire who’s basically been a liberal all his life. Perhaps that’s why we keep coming back to Rubio and Jeb and maybe now Christie.