And the Next Senator From Massachusetts Is ...

Who will win the special election on Tuesday to fill Teddy Kennedy's old Massachusetts Senate seat?

I have absolutely no idea. But to be fair, neither does anyone else. Which is why the battle between State Sen. Scott Brown (R) and Bay State Attorney General Martha Coakley (D)—a battle in one of the country's bluest states for a seat that could shift the balance of power in the Senate on the eve of President Obama's crucial health-care-reform vote—has energized Republicans, terrified Democrats, and gotten election junkies (like those of us here at Gaggle headquarters) all worked up for the first time in months.

A quick look at the polls released since New Year's Day will show how the Coakley-Brown cage match suddenly (and improbably) became the most exciting political story in the land. Once upon a time, Coakley led big. In November, for instance, Boston's Suffolk University released a poll of 600 registered voters that showed the Democrat clobbering Brown by 31 percentage points. At the time nobody noticed, largely because that's what Democrats are supposed to do to Republicans in Massachusetts Senate races: clobber them by 31 percentage points. But fast-forward to yesterday, when Suffolk released its second poll of registered Bay Staters. The results showed a 4-point lead—for Brown.

This would seem crazy—a statistical outlier, surely—if it weren't for the fact that many of the other polls that have materialized over the past two weeks have also placed Brown within striking distance.

On Jan. 4, Rasmussen released a poll of likely voters that gave Coakley a robust 9-point advantage; by the time the firm's Jan. 11 survey came out, however, her margin had narrowed to a measly 2 points. At least one Democratic polling organization, PPP, is now putting Brown in the lead, 48-47. Meanwhile, Coakley's edge in internal campaign polling has reportedly collapsed from 15 points last week to a mere 2 points on Wednesday. (Update: Marc Ambinder now says Brown leads Coakley by four points in these polls. Ouch.) Yesterday, both the Rothenberg Report and Five Thirty Eight switched the Massachusetts race from "Leans Dem" to "Toss Up." As Steve Kornacki writes, "The momentum clearly favors Brown ... [He] may actually win."

Without getting into the reasons why the Coakley-Brown race has suddenly become so close—Coakley's ineptitude; Brown's relative composure; dissatisfaction with Democrats in Washington; the terrible, horrible, very bad, no-good economy—I will note that all is not lost for Coakley. Yet.

For starters, she still leads in a bunch of polls: Research 2000 (+8); Mellman Group (+14); and Boston Globe/UNH (+17). Some of them were commissioned by Democratic outfits; some weren't.

Second, there's a ray of hope for Dems even in the surveys that don't appear as favorable at first glance: room for growth among voters who haven't yet decided whether they will vote. Take Rasmussen. On Jan. 4, voters who said they were "certain" to vote preferred Coakley 47 to 45; by Jan. 11 the same group had tilted in Brown's direction, 49-47. This makes sense—the party that's out of power is generally more likely than the party that's in power to turn out in off-year or special elections—and it pretty much explains why Brown was able to pull even with Coakley in the second Rasmussen sounding. But among voters who said they were "not certain" whether they'd vote on Tuesday—i.e., most of Massachusetts's electorate, which leans leftward and has therefore not been particularly fired up in recent months—Coakley crushed Brown by 37 percentage points, 63 to 26. In other words, there are a lot of potential Coakley voters waiting in the wings.

Which brings us to the third reason Democrats should stop their preemptive sobbing. Before about, oh, two days ago, Republicans basically had an enthusiasm monopoly in Massachusetts; grassroots activists were quick to recognize that electing Brown as the GOP's 41st senator meant possibly derailing Obama's health-care-reform legislation, and they've been organizing for him ever since. The Dems, by comparison, have been complacent—content (mistakenly) to let Massachusetts's old liberal tendencies work their magic. Not anymore. Over the last 72 hours, the contest has effectively become nationalized, with Obama himself planning to swoop in on Sunday and "the Coakley campaign, the and ... [now] devot[ing] significant media buys to negative attacks on Brown," as Pollster notes. Ultimately, this sudden surge of attention and money is likely to boost enthusiasm (and therefore turnout) on both sides. But Democrats simply have more to gain. As Mark Blumenthal puts it, "For every three previously disinterested voters who change theirminds and decide to vote this week, two will be Coakley supporters."

Does this mean I'm calling the race for Coakley? Hardly. It's anyone's contest to win. But I will be watching for movement in those "certain" and "not certain" categories as the latest ads begin to air and the latest flood of cash begins to trickle down. The next Rasmussen poll is out Monday. Hold on to your hats.