From an analytical standpoint, whether Scott Murphy remains ahead of Jim Tedisco after absentee ballots are counted (and that is anything but a sure thing) is largely immaterial. One of the candidates is going to win by not more than a hundred, maybe a couple hundred votes (and possibly by quite a bit less than that). The difference between winning and losing could be because someone's daughter got an ear infection and they drove her to the doctor instead of going to the polls, or someone happened to turn on their TV five minutes after a Tedisco commercial aired rather than five minutes before. When elections are decided by hundredths of a percentage point, there is a lot of luck involved.
But what does it mean, exactly, for the vote to have been split about evenly in this particular Congressional District?
What this very narrow fragment of evidence suggests -- it may be dangerous to overgeneralize -- is that not much has changed since last November. The PVI of NY-20 based on the 2000 and 2004 elections is R+3; based on the 2004 and 2008 elections, it's more like R+2. That is, NY-20 is between two and three points more Republican than the average Congressional District.
But keep in mind that the average Congressional District, at least in 2006 and 2008, had been highly inclined to vote Democratic. A Republican-leaning district at a Democratic-leaning moment in the political cycle is usually going to translate into being a toss-up -- and indeed, that's exactly what we find if we look at how the two parties performed on November 4th in districts that looked like NY-20:
Of 58 Congressional Districts with PVI's of between R+1 and R+4, the vote was almost an even split; Democrats were elected to the House in 30 of these districts on November 4th, and Republicans in the other 28. So our default expectation is that a district like NY-20 should indeed be a toss-up -- which is exactly what we wound up getting. The contest turned out about the same yesterday as we might have expected it to had it been held on November 4th.
The status quo, in other words, was more or less preserved. But the status quo, of course, is a much happier place if you're a Democrat than if you're a Republican...