The New York Primary is setting up as a big test for Bernie Sanders.
Throughout his run for the Democratic nomination, the Vermont senator has struggled with non-white voters. Those voters are a big part of New York's Democratic electorate. In 2008, they cast more than 30 percent of the Democratic primary ballots.
But if Sanders is hoping to make a run at the Democratic nomination, he's going to need to show he can win minority voters, or at least do better among them. They are a core part of the Democratic Party -- some 40 percent of the self-identified Democrats are minorities.
And New York could give the candidate an opening, or at least some points for familiarity among minority voters. Sanders, born and raised in Brooklyn, will gladly take any advantage he can get.
How bad has he performed with minority voters? So far 21 states have produced Democratic exit poll results, and in only one has Sanders has captured at least 50 percent of the non-white vote. That was New Hampshire, where he won 50 percent exactly.
Other than New Hampshire, his best showing was in Wisconsin, where he captured 43 percent of the non-white vote. And other states have been abysmal for the senator. He won 7 percent of the non-white vote in Alabama, 11 percent in Mississippi and 19 percent in Georgia.
Those states are in the South, where Sanders acknowledges he's had trouble winning votes. But even outside that region he's not done particularly well with non-white voters. In Iowa, he won 34 percent of the minority vote. In Ohio, it was 32 percent. And in Michigan, a state where Sanders pulled off an upset win, his support among non-white voters was only 34 percent.
These numbers are particularly worrying to Sanders because his path to the nomination relies on winning over Democratic superdelegates, the party elites (governors, senators, members of the House, members of the Democratic National Committee and former presidents) who can choose whichever candidate they like.
And its hard to construct a persuasive superdelegate argument for the Vermont senator if he can't find a way to win a voter group that is such a big part of the Democratic Party.
The reverse argument, of course, is that Democratic front-runner Hillary Clinton has struggled with white voters. That's true, but not to the same extent.
Clinton has won the white vote in 10 of the 21 states for which there are Democratic exit polls. And in some states she has won with large percentages. She captured 68 percent of the white vote in Mississippi, 58 percent in Georgia and 57 percent in Texas and Virginia.
In short, the numbers suggest her problems with white voters aren't as deep as Sanders' are with minorities.
The Sanders campaign needs to have an answer for those concerns. If he can find a way to win minority voters in New York, or if he can at least have a good showing, he could point to a major accomplishment.
But the numbers suggest Sanders has work to do in the next week. The latest NBC News/Wall Street Journal/Marist poll in New York shows him leading Mrs. Clinton among Latinos narrowly - 51 percent to 47 percent, but trailing badly among African American voters in the state (28 percent to 68 percent).
This story originally appeared on NBCNews.com