True, that assertion is nearly universal. I happen to disagree, but it's not a cut-and-dried sort of thing. What does "Democratic" mean? If it means electing Dem governors, that used to happen every time. If it means voting for Dem presidential candidates, that still doesn't happen. If it means electing a Dem legislature, that used to happen and now it's 2/3 GOP. If it means electing Dem Senators, it used to happen and now there are 2 Republicans.
They continously cite the growing Democratic vote in Fairfax County. True, it is putting a lot of Democratic votes on the table, and it no longer seems possible for a Republican to win the state by twenty points. On the other hand, conservative areas of the state are also fast growing, and there's little to show that Democrats are making as big inroads in the rest of the state as they are in Fairfax. I think you have a new, cosmpolitian Democrat vote emerging in the north, while old school yellow dog Democrats vote more Republican in the south, so in a way it is a tradeoff. In order for Fairfax to truly turn the state blue, it would need a large voting electorade on par with somewhere like Detroit, and I don't think that's going to happen any time soon.