In anticipation of a possibly close race in Massachusetts next Tuesday, some analysts are preparing to write off the race as a special election fluke. Marc Ambinder, who predicts that Coakley will win comfortably, writes as his first possible lesson for Democrats in his pre-mortem piece:

"Nothing at all. The race is unique. A six-week general election sprint, a winter election day that people aren't used to, the burden of replacing Sen. Ted Kennedy, a generally poor atmosphere for Democrats -- it's hard to transfer any lessons from this particular race to any other. It was easy for Scott Brown to rack up support while no one paid attention to the race. "

Nate Silver takes a slightly different approach. He looks at contested open-seat races in Massachusetts since 1980, at the Congressional, gubernatorial, and Presidential level, and concludes that "a close-ish Brown finish would not be quite as unprecedented as it has been made out to be; the state has often given the newbie a little freshman hazing and then fallen in love only later."

Without having any idea how this race will turn out (I think there's about a 25% chance Brown scores the upset right now, a 45% chance of a low-to-mid single digit race, and a 30% chance that the polls are just wrong, a la NY-23), I think these pre-mortems miss the mark. Ambinder's analysis that this is nothing more than a freak special election misses the forest for the trees. In particular, it reminds me of analyses that Republicans were writing in 2008, after they lost special elections in Republican districts in IL-14, LA-6 and MS-01. Any one of those by itself wouldn't seem that bad, but taken together, the message to Republicans was (or should have been) overwhelming: Very few districts are safe this time around. If this race is as close as Rasmussen and PPP are projecting, a lot of other Senators who think they are safe need to start running today as if they might lose, much as Martha Coakley did not.

Silver's analysis is a bit more problematic. I generally prefer a good quantitative analysis to a purely qualitative approach, but in an effort to do a quantitative piece, Silver compares apples to oranges to pineapples. As he notes, Governor's races are inherently different beasts than Senate races. With executives, voters look for general administrative competence more than they look for ideological stands on the issues. Hence, Rhode Island and Vermont have Republican Governors while Wyoming and Kansas have Democrats. If you remove the gubernatorial races from the calculation, the average Democratic margin increases from 56.2%-39.9% up to 58.2% to 38.2% (Interestingly, removing the POTUS races for similar reasons doesn't change the analysis at all), and we only have five races where the Republicans managed to score above 45% of the vote.

Including the Congressional races is also problematic, since Congressmen represent only a small cross-section of the state. Of the ten Massachusetts Congressional districts (eleven, going back to the 1980s), we see nine total races: one race for MA-01, one for MA-04 (in its 1970s iteration), three races for MA-05, two for MA-08, one for MA-09, and one for MA-10.

Had these races been evenly distributed across the state, the comparisons might not be that bad. But six of these nine races are from the most heavily Republican portions of the state (or at least the districts most open to voting for Republicans), two are from heavily Democratic portions of the state, and one is unknown (I believe MA-04 leaned Democratic in 1980, but don't have the data to back that up).

The 1990s iteration of MA-10 included territory that voted for Bush in 1988, even with Governor Dukakis at the top of the ticket. MA-05 went for Bush by his national average in 1988, gave Reagan 57% of the vote in 1984, and was one of G.W. Bush's best MA districts in 2004. And while MA-01 has been trending toward the Democrats for decades, in 1990 it was still a reasonably Republican district: Olver was the first Democrat to represent the district since the 1890s. Indeed, had the GOP not run the darling of the state's New Right against Olver in 1990, or had avoided a candidate who called himself the "Newt of the North" (referring to Speaker Gingrich) in 1996, they might have won both districts outright. The bottom line is that the Republican formula for success in Massachusetts is to perform well in MA-5, MA-6, and MA-10, do well in MA-2 and MA-3, and try to tamp down losses elsewhere. These three districts make up almost half of our Congressional dataset. This overrepresentation of the most Republican-friendly portions of the state skews the average even more toward the Republicans, and cannot be compared to a statewide Senate race.

Ultimately what we're left with is a GOP that has never managed to get within seven points of a Senate seat in Massachusetts since 1972. And that seven-point defeat came while running a very, very moderate Governor who had won re-election a two years earlier with over 70% of the vote against a Senator who had never been very much beloved by the state.

Here, we have a virtually unknown state Senator who is promising to vote against the Democrats' top legislative priority taking on a sitting Attorney General. Probably the closest analogue would be Kerry's 1984 race, when he was a sitting Lieutenant Governor facing off against a conservative millionaire. Kerry won by ten points in the midst of the Reagan landslide. And let's remember, a high-quality candidate in Mississippi (a state about as Republican as Massachusetts is Democratic), running in the best Democratic year in decades lost by ten points.

So if Scott Brown makes this a low-single digit race it will be unprecedented - and it will be a big deal.