My very cautious estimate of Obama’s margin of victory in Fairfax County is 67,538. My optimistic estimate is that the margin will be 117,884. I detail how I came to each of those numbers below. But I guess I’ll split the baby. I predict that Barack Obama wins Fairfax County by a margin of 92,711 votes.
There are 657,393 registered voters in Fairfax County which I am going to round off to 660,000 in order to account for the yield from the frenzied last days of voter registration leading up to the October 6th deadline. And assuming a turnout of 87% (high but not totally unrealistic given that in 1992 arguably the last truly competitive presidential campaign in Virginia the state saw an 84.5% turnout) – 574,200 people will vote in Fairfax County.
Cautious Estimate: Even without getting into the tricky analysis of the recent demographic shifts which favor the Democrats I have a very conservative projection of Obama’s Fairfax County margin of victory. I arrived at the projection by merely allocating the portion of the above projected vote total that voted in 2004 exactly as it was allocated in 2004 – Kerry voters to Obama and Bush voters to McCain ( an incredibly conservative estimate from Obama’s perspective given the aforementioned demographic shifts and dysfunctional state of the local Republican party) and then allocating the additional vote by 65% to Obama and 35% to McCain to vaguely reflect the demographic identity of the newest registrants (again conservative from Obama’s standpoint given the thorough superiority of Obama’s ground game in Fairfax County).
245,671 – Kerry vote
+ 73,334 – 65% of new voters
319,005 Obama votes
211,980 – Bush vote
+ 39,487 – 35% of new voters
251,467 McCain votes
Optimistic Estimate: This analysis is much more simplistic. Instead of trying to disaggregate newer and older voters from limited data I have just used the past two statewide election results – 2006 U.S. Senate and 2005 Governor – and averaged the Republican and Democratic percentile performance in Fairfax County among those two years and applied that to my turnout projections.
59.525% x 574,200 = 341,793 Obama votes
38.995% x 574,200 = 223,909 McCain votes