According to the US Census, the state of Virginia grew by 184,000 people between 2010 and 2012. 115,000 of that (63%) occurred in the major jurisdictions in Northern Virginia (Arlington County, Alexandria City, Fairfax County, Fairfax City, Falls Church City, Loudon County, Prince William County, Manassas City).
http://quickfacts.census.gov/qfd/maps/virginia_map.html
I didn't add the numbers for the rest of the state, but it looks like most of the counties in Southwestern Virginia (Republican stronghold) lost between 1-5% of their population between 2010 and 2012.
The other growth areas appear to be the Virginia Beach area and Richmond city.
If these trends continue, NOVA will increase from almost 30% of the state population to about 40% of the state population by the 2030's.
I think with NOVA at 40% (assuming no dramatic shifts in demographic voting patterns) we can safely move Virginia from purple to blue state.
We won't know until we see real votes. I think Virginia will match the national vote for two more elections before it moves center-left. Republicans must learn how to campaign there though.
