The conventional wisdom of the Coakley v. Brown special election in Massachusetts had congealed before the polls even closed in the Bay State. It was best exemplified by television punditry from the likes of John King and the dire warnings for Democrats from folks like Senator Evan Bayh.

But the "tack back to the center" crowd ignores a critical stat from yesterday evening: 44% of the people who cast a ballot for Barack Obama in 2008 in the state of Massachusetts either (a) cast a vote for Scott Brown, (b) cast a vote for Joe Kennedy, or (c) withheld their vote. The math tells us that option (c) was the most likely of the three.

Indeed, a good deal of Martha Coakley's problem last night was that communities that were absolute strongholds for President Obama in 2008 failed to turn out in the numbers that were necessary for a Democratic win.

Consider the evidence:

With all precincts reporting late Tuesday evening, the two-party turnout in this special election was just over 2.2 million voters. This comprises about 74.4% of the two-party turnout in the Obama-McCain election of 2008. On the surface, that was a very impressive turnout, slightly exceeding the midterm general election turnouts in 2006 and 2002.

However, a quick look at the Democratic strongholds in the state tell a different story.

I identified a total of 31 Democratic strongholds in the state by using the following criteria: the community had to have over 10,000 voters in 2008, and President Obama had to get two-thirds of the vote there.

In only 11 of the strongholds did turnout exceed the statewide average yesterday. In fact, in nearly half of them, the turnout was less than 70% of the turnout from fourteen months ago.

Meanwhile, over a dozen of the Democratic strongholds had lower turnout rates than Scott Brown's worst stronghold in terms of turnout (defined as communities of the same size, carried by Brown with 60% or more of the vote).

How many votes were left on the table? In Boston alone, a turnout at merely the state average (vis-a-vis 2008 turnout) would have been worth an additional 19,000 votes. Lawrence (which was the bottom of the pile, at 51% of 2008 turnout) could have provided another 4500 votes with a state-average turnout.

Would boosting Dem turnout have swung the election on its own? It is extraordinarily doubtful. But the bottom line is a painful one: a lot of races become vulnerable with the kind of depressed base turnout we saw yesterday in Massachusetts.

There is a lesson there for Democrats, to be sure. Whether they choose to learn it, however, remains to be seen.