A new poll from CNN and WMUR (New Hampshire's ABC affiliate) finds Bernie Sanders behind Hillary Clinton among Democratic primary voters by 8 points:

This is the third poll in recent weeks to show Sanders within striking distance of Clinton. Two from earlier this month by Morning Consult and Suffolk University put Sanders 12 and 11 points behind Clinton, respectively.

But there are reasons for skepticism. CNN and WMUR characterize the latest poll as a "statistical tie," but that's deeply misleading. The poll shows an 8-point lead with a 5.2 margin of error, which implies that the odds Clinton is truly ahead are in excess of 90 percent. What's more, a Bloomberg/St. Anselm College poll released before CNN/WMUR's but after Morning Consult and Suffolk's put Hillary a whopping 32 points ahead. Averaging the four together, that's a 15.5-point margin for Clinton. It's also worth asking if the polls showing Sanders gains are actually evidence of Clinton slipping. As the Washington Post's Philip Bump notes, the share of voters choosing a "not-Clinton" candidate, be it Sanders or Joe Biden or Elizabeth Warren, has held relatively steady; it's just that as polling firms have stopped asking about Warren (and to a lesser extent Biden), Sanders is uniting the anti-Clinton vote.

All that being said, the fact that Sanders has become the de facto anti-Clinton candidate is surprising, and a big deal. He's clearly making a strong appeal to the Democratic base in New Hampshire, one that Martin O'Malley, Jim Webb, and Lincoln Chafee have all failed to make. It doesn't hurt that he's from a neighboring state, and New Hampshirites wind up getting a lot of Vermont news, boosting his name recognition.

There's a long history of upset wins in the New Hampshire primary by insurgent candidates who wind up going nowhere. There was Pat Buchanan's victory in 1996, John McCain's in 2000, and Gary Hart's in 1984, to name a few. These three polls suggest that Sanders has an outside chance of joining their ranks. Just as a matter of political trivia, it'd be pretty funny if Hillary loses the primary to a senator from a neighboring state and the press treats it as a real setback, even as Bill Clinton lost the New Hampshire primary to a former senator from a neighboring state and the press treated it as a de facto victory.

But Sanders has a long way to go in appealing to voters outside New Hampshire's idiosyncratic and racially monochromatic electorate. His ability to appeal to the black and Hispanic voters who make up the Democratic party's national base is, as my colleagues Jon Allen and Dara Lind have noted, untested, and Clinton is beating him in the "invisible primary" of party elites by a wide, wide margin.