Democrats wondering if their hopes of keeping the Senate could receive any more hits this week got their answer yesterday: a new poll found Scott Brown trailing incumbent Senator Jeanne Shaheen by just two points. It’s either an outlier or a lagging indicator–more likely an outlier, but bound to give Democrats a scare either way.

That’s because if the race appears close, they’ll have to spend time, money, resources, etc. trying to fend off a challenge from an opponent given a new sense of momentum and likely able to improve his own fundraising on the news of apparently improving poll numbers. And at this point, with the way the Democrats’ luck has been going, they’d be tempting fate to dismiss a sign that their standing might be going from bad to worse.

As Andrew Stiles notes over at the Washington Free Beacon, the Democrats’ woes can be chalked up to two prominent factors, in addition to their affiliation with President Millstone: Republicans have recruited good candidates, and Democrats have recruited a mix of bad candidates and bonkers candidates.

The bad candidates include those like Iowa’s Bruce Braley and Kentucky’s Alison Lundergan Grimes, the latter a good candidate on paper but an almost shockingly terrible public speaker. There are struggling incumbents like North Carolina’s Kay Hagan and Louisiana’s Mary Landrieu. And then there are candidates like the Democrats’ two choices thus far in Montana.

Incumbent Senator John Walsh was running for reelection, but bowed out due to revelations of plagiarism. The Democrats replaced Walsh on the ballot with a state representative and radical leftist named Amanda Curtis. Readers, meet Amanda Curtis:

So the last thing Democrats want to deal with is a possible upset in New Hampshire. And yet, there are good reasons not to ignore this one poll. One such reason is because their opponent is Scott Brown. He did, after all, win Ted Kennedy’s Senate seat after Kennedy died and while promising to vote against the major domestic reform proposal that was being sold in Kennedy’s name. Brown has been an underdog before, and the result was a Republican senator in uber-liberal Massachusetts.

Another is the flipside of one of Brown’s current weaknesses. He has switched states to run for this seat, losing his local-boy authenticity and having to build connections he could take for granted in his original home state. He also opens himself up to the charge of carpetbagging, though it’s not always a terribly effective accusation in the course of an election. But the other side of that coin is that he’s trading in an overwhelmingly liberal state for one with a more conservative streak. As a Republican, he’ll spot his opponent fewer points in New Hampshire than he did in Massachusetts.

Another reason for Democrats not to be too dismissive of the poll is that if Brown ends up winning this election, they will never hear the end of it. He would cause a much larger headache for national Democrats as a senator from New Hampshire than he could from Massachusetts. In both, of course, he gets only one vote. But in New Hampshire he’d have a stronger incumbency and a national profile because of the state’s role in presidential nominations, especially on the Republican side.

That means that if Democrats lose the New Hampshire seat to Brown, they will be witnessing the establishment of a genuine national politician. Unless his career there is a disaster, he will instantly be the subject of presidential speculation (which he will no doubt feed). If he doesn’t run for president, he will at least be a much sought after endorsement for aspiring Republican presidents. The spectacle of early-primary-season New Hampshire will now include a procession to the throne of Scott Brown.

So losing the seat to Brown is more than just another Senate seat, notwithstanding the fact that the midterms might be close enough that one Senate election really can determine who is in the minority and who the majority. Expect, then, this poll to refocus attention on New Hampshire. If that happens, Brown’s fundraising will increase. And if that happens, Shaheen will need more help from the national party and major donors as well. That would draw money away from other races, a serious hit for a party that is already on the defensive for November’s midterms.

Brown is still behind in New Hampshire, and probably by more than this latest poll suggests. But Democrats have already learned how dangerous it is to underestimate him.