Virginia's Democrats are holding a primary today, and the headliner event is the contest to see who will face Republican Bob McDonnell in November in an effort to secure a third straight Democratic governorship. As Jonathan Martin of Politico explains this morning, there are scenarios under which each of the three candidates--Creigh Deeds, Terry McAuliffe and Brian Moran--could win, with turnout being a crucial variable. But Deeds has been the surprise leader in all four of the polls released during the last week.

I have a post up at fivethirtyeight.com that explores some of the issues we may be discussing when the returns are in, including the ancient debate between mobilization and persuasion strategies; the role of timely media endorsements; and Virginia's relatively restrictive early voting rules, which Gov. Kaine unsuccessfully tried to change this year.

The polls in VA close at 7:00 p.m.; the whole state's in the eastern time zone; and given the expected low turnout, we may have a result pretty early unless it's very close.