If you’ve been following the Christie-versus-Paul “battle for the soul of the GOP” meme since Friday, don’t miss this important gloss from Pew. How major has the “major swing” among tea partiers been? Feast your eyes:

Three years ago, at least a plurality of every ideological segment except moderate Democrats thought the feds didn’t go far enough to protect the country. Three years later, nearly every segment has swung the other way. The only holdouts are moderate Democrats (oddly) and moderate Republicans. More specifically, non-tea-party Republicans tilt 41/43 towards thinking the feds haven’t done enough to protect the country; among tea partiers, the tilt is … 55/31 towards thinking they’ve gone too far in restricting civil liberties, a 35-point(!) swing since 2010. That’s what a battle for the soul of the party looks like — a double-digit spread among the centrist and conservative wings on a key point of national security.

Normally I’d dismiss a turnaround as sharp as that as driven by partisan reaction to the White House. Elect a Democratic president and you’ll see Dems warm to his counterterror program and Republicans sour on it, no matter how much it resembles the last GOP administration’s program. But Pew’s reference point here isn’t an earlier poll taken during the Bush era; it’s 2010, nearly two years into Hopenchange. This shift has happened entirely on Obama’s watch. And it’s not just Republicans who’ve decided that the feds have gone too far. A narrow plurality of Democrats now agree. It’s bipartisan and it’s recent — although it’s most pronounced on the right:

On the specific question of NSA surveillance, the tea party is net -28 and the rest of the GOP is +6, which raises two questions. One: How does Chris Christie or Rand Paul bridge that gap as nominee in 2016? I’m tempted to say that it won’t matter much, that government spying is, for better or worse, a marginal issue in a primary vis-a-vis cutting spending, immigration reform, etc, but it won’t be marginal next time thanks to Paul’s presence in the race and prominent hawks’ insistence on attacking him early. Gonna be a lot of hard feelings when the dust settles; who knows what that means for the general election. Two, more importantly: Why such a shift against surveillance since 2010? Much of it, I assume, is recent, a reaction to Snowden’s revelations about the extent of the spying. But I think Paul’s ascendance is another factor, at least on the right — not because the NSA was a major talking point for him until this year but because his prominence as a defender of the tea party is bound to make tea partiers more sympathetic to his overall agenda on civil liberties. That’s been his plan all along, to turn the TP from a movement focused narrowly on spending and taxes into a broader libertarian movement. He’s made major inroads on that if Pew’s data is right. How durable that influence will be if/when America elects another Republican president and the White House insists on maintaining robust surveillance, I don’t know. Some of this is being driven by antipathy to, and distrust of, Obama specifically. The question is how much.

Having said all that, I want you to click and eyeball the first graph on Pew’s page. Skepticism among the general public abounds about whether court oversight of the NSA program is adequate, whether the data collected is being used properly, whether the government’s collecting only metadata or something more — and yet, when push comes to shove, 50 percent approve of the program versus 44 percent who disapprove. Among people who think the government has read their own personal communications, 40 percent nonetheless support surveillance. That’s right in line with last week’s WaPo poll which found 51 percent think the NSA program is justified versus 40 percent who think it isn’t, even though a chunk of that 51 percent also think the program is too intrusive. That is to say, there’s some segment of the public that supports the surveillance state despite being under no illusions about its perils. They know they’re being spied on, they don’t like it, but they’re willing to tolerate it in the name of catching bad guys. The only way to move the needle on that, I think, is if a Republican is elected in 2016 and the tea party maintains its robust opposition to surveillance. In that case, a bunch of Democrats will swing from support to opposition on partisan grounds and that, along with the tea party’s opposition, will make a new majority. Is the tea party likely to be that steadfast, even with a GOPer in the White House? You tell me.