Bernie Sanders will live to fight another day. The senator was expected to win overwhelmingly on Super Tuesday in his home state of Vermont, and his campaign would have stalled if that were the extent of his victory. But he won in Oklahoma, Minnesota, and Colorado, and ran a tight race in Massachusetts, giving his political revolution a new lease on life. His rival Hillary Clinton won overwhelming majorities, as expected, in the Southern states: Georgia, Virginia, Alabama, Tennessee, Arkansas, and Texas.

In his speech early on Tuesday night, Sanders vowed to continue the fight till all 50 states have spoken. At the end of tonight 15 states will have voted,” he said. “Thirty-five states remain, and let me assure you that we are going to take our fight for economic justice, for social justice, for environmental sanity, and for a world of peace to every one of those states.”  

It could be argued that both Sanders and Clinton are regional candidates, with Sanders dominating the Northeast and Clinton the South. But there is another way to slice the numbers—one that presents a problem for Sanders not just in terms of winning the primary but also in terms of the logic and legitimacy of his movement. Clinton is winning a multiracial coalition that includes large numbers of whites, African-Americans, and Latinos. Sanders by contrast is winning largely in states which are overwhelmingly white: Iowa, New Hampshire, Vermont, and Oklahoma. 

There are two exceptions to this rule: Colorado (a state that is 21 percent Latino) and Nevada, where Sanders made significant inroads with Latinos (according to a disputed entrance poll, he won a majority of them). Colorado and Nevada do show Sanders can expand his popularity into the Latino community, although even here much work needs to be done. 

To see Sanders’s ongoing diversity problem, consider Texas, where Clinton won narrowly on Tuesday among whites (51 percent to 47 percent) but overwhelmingly among both blacks (80-18) and Latinos (67-33), according to exit polls.

These numbers show that Clinton’s support much more closely mirrors the Democratic Party’s base than Sanders’s does. One of the key divisions in American politics is that the Republicans are an overwhelmingly white party, while the Democrats are a multiracial one. In 2012, the Obama coalition consisted of 56 percent white, 24 percent black, 14 percent Latino, and 4 percent Asian. By contrast, Mitt Romney’s electorate was 89 percent white, 2 percent black, 6 percent Latino, and 2 percent Asian. Clinton’s coalition, in both Texas and elsewhere, looks like Obama’s; Sanders’s looks like Romney’s. 

The Sanders campaign seems resigned to the whiteness of his support, and reportedly intends to make the most of it. According to Kyle Cheney writing in Politico:

Sanders’ goal was to emerge from Super Tuesday with a viable comeback path. But it’s unclear how he envisions proceeding from here. His team has sketched a strategy that involves running up margins in the predominantly white states that have responded better to his message. He’s hoping to rattle off wins in the weeks ahead in friendlier territory — Nebraska, Kansas and Maine, which are next on the calendar.

This strategy might be dictated by necessity given Sanders’s failure to gain traction among black voters and limited success among Latinos. But whatever the cause, by having such a narrow demographic base, Sanders has a much harder time claiming to represent the Democratic Party than Clinton does. 

Photographs of the speeches the candidates gave tell their own story: Clinton was surrounded by a diverse, racially mixed crowd (including a woman in a hijab) while Sanders, speaking from his home state in Vermont, had a largely white crowd behind him. 

Sanders remains the underdog in the race. If he wants to win it, he has to find a way to win over more non-white voters. Failing to do so will leave his political revolution fatally unrepresentative of both America and the party he only recently called his own.