Hillary Clinton has won Virginia's Democratic primary, according to projections from multiple media outlets.
Clinton was heavily favored to win Virginia. The state's Democratic electorate has a substantial number of black voters, who supported Clinton overwhelmingly in Nevada and South Carolina. She was ahead by 20 points in preprimary polling, and the Sanders campaign didn't put as much energy into campaigning there as it did in some of the other states up for grabs today.
According to exit poll estimates, the electorate appears to have skewed toward older voters. That’s bad news for Sanders, who performs best among young people. Furthermore (assuming the exit polls are correct), the small turnout among young voters has a larger negative implication for Sanders: that the coalition of voters he needs to bring about "political revolution" just isn’t materializing.
What does this mean for the Democratic race?
The real measure of how important Virginia is to the broader Democratic primary battle is whether it makes it more likely or less likely that Bernie Sanders will be able to catch up to Hillary Clinton's support. Because the primary calendar is spread out, it's totally plausible that Clinton could come out to an early lead as her stronger states vote early — then watch it evaporate as pro-Sanders states turned out to the polls later. (Or vice versa.)
One way to figure out if Clinton's lead is temporary, or if Sanders is running out of time to close the gap, is to start backwards. If Sanders and Clinton had exactly equal amounts of support among all Democratic primary voters in America, what would the race look like right now? What would have happened in Iowa, New Hampshire, Nevada, and South Carolina, and what would happen in the Super Tuesday states tonight?
Nate Silver and the team at FiveThirtyEight have one way of estimating that. They use the demographics of each state to predict how much that state would "lean" toward Clinton or Sanders if the race were evenly tied nationally.
According to that model, if Sanders were tied with Clinton nationally, he'd be losing to her by 9 points in Virginia. So while the outcome of this race might not be as important to the Sanders campaign, the margin of her victory might be something that they should watch closely.