Hillary Clinton has won the Arkansas Democratic primary, according to projections from CNN.
Clinton was always expected to win Arkansas. It is basically her home state; she was its first lady. And it has a large population of African-American voters, among whom she's done very well in the Nevada caucuses and South Carolina primary.
What does this mean for the Democratic race?
Anyone can win her home state. The real measure of how important Arkansas is to the broader Democratic primary battle is whether it makes it more 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 work backward. 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 tied nationally.
According to that model, if Sanders were tied with Clinton nationally he'd be losing to her by 15 points in Arkansas. But the demographic model doesn't account for the fact that Clinton probably got a hometown boost. It's safe to say that this isn't a loss Sanders supporters should sweat — but it means about as much as Sanders winning Vermont.