He takes CNN/ORC polling data on the race since last January and tracks support for 4 of the candidates based on whether or not the responders identify with the Tea Party. Here's a graph of the results.
Browstein's point is that while the non-tea partiers have coalesced around Romney, the tea party crowd is still vacillating in their flavor-of-the-month search for purity. Romney is still standing after Pawlenty dropped out, Huntsman tanked, and the rest of the possible contenders knew better than to stick their toe in these insane waters. But the Tea Party vote is either divided or in chaos - depending on who is up at the moment.
This is causing folks like Adam Brandon, spokesman for Freedom Works, to loose sleep.
Brandon says what keeps the group "up at night" is the fear that tea party voters will never solidify behind a single candidate and allow Romney to win the nomination even if most hard-core conservatives still oppose him.
That's the scenario most "serious" analysts are betting on. But Brandon might not be ready to throw in the towel quite yet.
Which is why he says FreedomWorks, which has never endorsed in a presidential primary, may feel compelled to do so this year. "If there's the establishment Romney vote on one side, and there are two of these two party candidates battling it out, which might mean he would slip in, we might have to endorse," he says.
I suspect the first step in that process is what happened yesterday when another Tea Party group, American Majority, told Michele Bachmann that she should get out of the race.
So Tea Party, who's it going to be? Cain, Perry...or Gingrich?