Just as Donald Trump has caught the imagination of a disaffected GOP base, Bernie Sanders has done the same in the Democratic Party. He’s filling arenas while the supposedly Inevitable II Hillary Clinton struggles in smaller venues. In the latest Franklin Pierce University/Boston Herald poll, Sanders has now done what Barack Obama took longer to do eight years ago — surpass Hillary in a key state for the nomination:

Democratic presidential hopeful Bernie Sanders has rocketed past longtime front-runner Hillary Clinton in New Hampshire, a stunning turn in a race once considered a lock for the former secretary of state, a new Franklin Pierce University/Boston Herald poll shows.

Sanders leads Clinton 44-37 percent among likely Democratic primary voters, the first time the heavily favored Clinton has trailed in the 2016 primary campaign, according to the poll of 442 Granite-Staters.

Vice President Joe Biden got 9 percent support in the test primary match-up. The other announced Democrats in the race, former Maryland Gov. Martin O’Malley, former Rhode Island Gov. Lincoln Chafee and former Virginia Gov. Jim Webb, barely register at 1 percent or below.

Five months ago, Hillary had a 37-point lead over Sanders, 44/7, in a poll in this same FPU/BH series. That’s a 44-point swing in the gap in just five months, a stunning rebuke to Clinton, and much of that came in the last few weeks. Just last week, WMUR showed Sanders only back by six points, 42/36.

The Pierce poll shows several danger signs for Hillary, and for Democrats who lack any realistic options at the moment. Hillary still has higher favorability ratings in this poll than Sanders, but that’s now within the margin of error (80 to 76). Sanders’ favorability has shot up 20 points in five months, while Hillary’s has edged downward by four — and her unfavorable responses rose from 12% to 18%. Furthermore, most of Sanders’ favorability is “very favorable” (54 points), while less than half of Hillary’s is “very favorable” at 36 points. (Joe Biden has a 79% favorable rating, but only 25% of it is “very favorable.”)

That trend gets reflected in the enthusiasm numbers, a particular vulnerability for Democrats who need to generate excitement to win in a general election. Only 35% of respondents described themselves as “excited” about Hillary Clinton’s candidacy, with a majority unenthusiastically supporting her (51%). Interestingly, the numbers aren’t wildly different for Sanders; just 44% consider themselves excited, while 36% “support some of his ideas” but don’t think he could win a general election.

And this, mind you, is among Democrats.

This could be a disaster waiting for Hillary, who didn’t do well in Iowa eight years ago and needed the Granite State to recover against Obama. On the other hand, New Hampshire requires primary candidates to be registered to the party on whose tickets they run, and … Sanders is still not a Democrat, but an independent Socialist.  The Democratic Party in New Hampshire has said they will certify him, but any person with standing in the state can challenge his qualification to be on the ballot. Does anyone want to bet that Team Hillary lets that opportunity go to waste?

Even if they challenge it, though, the problem remains, and not just for Clintonistas. Hillary 2016 is exciting people as much as Hillary 2008 did. If Hillary’s doing this poorly among Democrats while desperately tacking leftward, she’s going to get clobbered in a general election — and they have no realistic Plan B.