Is Virginia a must-win state for both parties?

[Mehmentum]

Its not a must win for either party at this point, though its closer to must win for the Democrats than the Republicans because of its slight Democratic tilt.

Without Virginia, the Democrat's best path is Obama's 2012 victory without FL, VA, and OH.  Its a very narrow path, however.  Maybe they could manage a win with Ohio.

Without Virginia, Republicans would need something like IA, CO + NH/NV, IA + WI (which is a 269 tie that the GOP wins in the house), or just PA.  Of course, the challenge is actually winning PA or WI.  So far the GOP hasn't had luck with that, so they'll need to bet that 2016's the year these states finally flip.