5. As an outsider (I live in MD, just north of DC): Most simply...
the largest metropolitan area in the state, the one with nearly 40% of the population...is NoVA, the southern suburbs of DC. It basically functions more as part of DC than it does part of VA. The people there ID with DC, not VA.
It'd be like the effect on TX if NYC was 0.2 miles over the OK border so all the wealthy educated increasingly-liberal people from the city looking for reasonable cost-of-living and nice places to raise their kids started flooding into N. TX. Add into that the coastal area around Hampton Roads, Norfolk, VA Beach is rapidly becoming a metro-region city, which means it's also becoming less Republican...and the writing is on the wall.
As DC residents, we joke about the Woodbridge line. North of Woodbridge, VA you're not really in the South. Everybody commutes into DC to work, to play, to live. South of Woodbridge, it's an entirely different state...but one that is shrinking both in area as the DC suburbs expand and population.