Bernie Sanders's campaign manager Jeff Weaver vowed Monday that his candidate is going all the way to the Democratic convention in July.

That may be the case -- but the reality is that after Nevada last weekend, Sanders's path forward just got a lot tougher.

The Vermont senator's 6-point loss in Nevada on Saturday is one that will reverberate down the map for him. And ultimately, the results there say just as much about Sanders's weaknesses going forward as they do about Clinton's strengths.

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Next up on the calendar is South Carolina, a state where polling shows Clinton with a double-digit advantage over Sanders. It's also a heavily African American state, a demographic among which Clinton still has strong support. After that, the map expands out to Super Tuesday and beyond.

"His team is probably looking at the exact same map that Hillary Clinton's is and is starting to feel the challenge," said Lynda Tran, a former Obama official.

Here are some challenges Sanders faces going forward:

Minority support

Team Clinton's argument has long been that even though Sanders was well-suited to the first two states on the map, Iowa and New Hampshire, those two (heavily white) states aren't representative of the country as a whole--and that Clinton's the only candidate who can fare well among minority voters nationwide.

While there's some question of who had the edge among Latino voters in Nevada last weekend--entrance polls put Sanders ahead 53 percent to 45 percent with the demographic, but the Clinton campaign contends that those polls didn't accurately reflect their candidate's support among Latinos and that Clinton actually won big in the most heavily Latino precincts in the state.

Regardless, Clinton did get the overwhelming support of Nevada's African American voters: according to entrance polls, she won them by a 76-to-22 margin. Polling out of South Carolina gives her a similarly strong advantage among African Americans, a demographic that's crucial there.

Sanders, on CBS's "Face the Nation" on Sunday, noted that his campaign still has some work to do with African American voters, though he argued that the more familiar they become with his platform the more support he'll get. "We are making inroads. We are doing better," he said. "...But you're right, we have a lot of work to do."

Looking ahead to the Super Tuesday map, there are a handful of states where African American voters will play a similarly large role: Alabama, Arkansas, Georgia and Virginia, to name a few, are all Super Tuesday states with large African American populations.

There are still some states coming up with demographics that mirror Iowa and New Hampshire a little more closely, like Vermont, Sanders's home state, which also votes on Super Tuesday. But with a bigger map, his lack of momentum among African Americans will be a real problem.

Campaign cash

There's also the money aspect, which will only grow more important as the campaign heads into March and the map expands dramatically. While only four states cast their votes in February, 28 will vote in March--giving both campaigns a huge swath of territory to cover. And that's the time when money matters the most: he can't be on the ground personally in each state, so he'll need to get his message out in other ways.

For Sanders, though, who has had remarkable success with online and small-dollar donations, March is coming at exactly the wrong time. The candidate's campaign poured resources into Nevada--outspending the Clinton campaign on the airwaves, for example, and hiring 100 staffers on the ground to even the score before the caucuses--and, as of the beginning of February, has just $14 million in its war chest. (Clinton's campaign, by contrast, still had $33 million in the bank at the start of February.)

Sanders said Sunday on NBC's "Meet the Press" that his campaign is focusing especially Minnesota, Colorado, Massachusetts, Vermont and Oklahoma for Super Tuesday, with midwestern states like Illinois and Michigan further down the line in March. (As of earlier this month, he had bought TV air time in Minnesota, Colorado, Massachusetts and Oklahoma.)

"The burden is on insurgent campaigns to win as many early states as possible and use that momentum to win in later contests, where they may face an organizational deficit," said Ben LaBolt, the lead spokesman for Obama's 2012 campaign. "But if Senator Sanders only wins one of the first four states, can't match the organization the Clinton campaign began building months ago in Super Tuesday states, and fails to mobilize African American voters, his quest for the nomination could end sooner than many pundits predicted even with his strong fundraising capacity."

The turnout equation

In order for Sanders to be broadly successful going forward, he needs to fundamentally change the electorate that comes to the polls (as then-Sen. Barack Obama did in 2008). But thus far, turnout has been a mixed bag--and it's unclear whether there's much of an opportunity in coming states to see the kinds of record turnout he would need to expand the map.

The voters he'd need for a big victory--say, college kids--are not known for their reliability. And when you factor in that March means spring break for a lot of students, who as a result may not be on campus for primary or caucus day, that vacation week could cost Sanders support in a handful of key states. (Not even factoring in Super Tuesday, Politico estimates the number of college students who could be on spring break in states with primaries from March 5 to March 26 to be more than half a million.)

Sanders himself said the low turnout in Nevada was a big part of why he lost there. And while he did better in Iowa and New Hampshire, the turnout decline was evident there as well: compared with 2008, Democratic turnout dropped 28 percent in Iowa and 13 percent in New Hampshire.

"The voter turnout was not as high as I had wanted," he said on NBC's "Meet the Press" Sunday. "And what I've said over and over again, we will do well when young people, when working-class people people come out. We do not do well when the voter turnout is not large. We did not do as good a job as I had wanted to bring out a large turnout."

Proportional delegates

None of this is to say that Sanders is done for: the fact that Democrats award their delegates proportionally means that even if he's not notching huge victories on Super Tuesday, he can still pick up delegates along the way.

"I assume Bernie Sanders stays in this race, continues to get convention delegates, goes to the convention even if she's got the nomination wrapped up, presses his cause," USA Today's Susan Page said on CBS' "Face the Nation" on Sunday.

But just as it's difficult to deliver a knockout punch in a proportional system, it's also difficult to chip away at a frontrunner's delegate lead once they get going. If Clinton picks up a few big victories on Super Tuesday and carries that momentum forward--not to mention her big lead among Democratic superdelegates--it could be very difficult for Sanders to catch up.

Clinton "started with such a tremendous advantage among superdelegates that as [Sanders] is taking less and less of the share of the pie going forward, it's just going to be less and less viable for him," Tran said.