The importance of early votes & absentees: Virginia's presidential results by congressional district

At Daily Kos Elections, we try hard to verify the accuracy of the Pres-by-CD numbers we give you by calculating the numbers ourselves. We didn't do this in a few states where the legislature provided these numbers for us. Apparently, we should have'at least in Virginia.

In its calculations, the Virginia legislature, in addition to providing too few significant figures, apparently also failed to include absentee votes in its calculations. (As a humorous sidenote, this all came about because David Nir and I were looking into the Virginia results, which showed VA-10 being '50% - 50%' and us wondering who actually won the district.) From their perspective, it could be reasonable to exclude early votes'not much research has been done into how early votes can be allocated to a given precinct (or area) when early votes/absentees are presented in aggregate across the jurisdiction (this doesn't excuse, of course, their exclusion of absentee votes even when an entire county is contained within a given district). We've ran into a similar difficult preparing data for the DRA, and of course several years back in the 2008 Pres-by-CD project.

At DKE, though, we are fairly adamant about splitting absentees and early votes properly'after all, an early or absentee voter votes for Congress, just like everyone else. We've been applying a fairly consistent set of methodologies, depending on how detailed early voting data is presented (or, for that matter, not presented; over the flip, we detail the exact methods that we've used). In Virginia, absentee votes are certainly important'there were about 500,000 such votes, and Barack Obama won 62 percent of them. (Put differently, without absentees, Obama won the state by 3.4 percent; he actually carried the state with a 6.3 percent margin.) We used both methods here to compare to the legislature's numbers (and our attempt to reproduce the legislature's numbers). At the district level, the impacts were as follows:

(The results for the subdivision method, which we're adopting moving forward, are available here.) Based on the similarity of our calculations with no absentees and the legislature's numbers, we're fairly confident that that is indeed the exclusion in how the legislature performed its calculations. Further, there are substantial differences once absentees are added into the mix'for example, Scott Rigell is actually in an Obama district. (It does turn out that Obama won VA-10, even without absentees allocated.)

While we had been using the old set of numbers in our judgments of the race, these revised numbers will be in our information set moving forward. Further, we will also be verifying that a similar issue does not exist in the other states. This yields us two benefits'first, we can confirm or question the accuracy of numbers presented in other states, but second (and perhaps more importantly), we can show actual vote totals (and not just percentages), as well as breakouts by county. As always, any redistricting-related work that we do is available from our consolidated redistricting resources page.