In the wake of his fourth-place finish in Iowa and fifth-place finish in New Hampshire, the candidate struggling most notably is Joe Biden, who was considered the race’s clear front-runner less than two weeks ago.

But Sen. Elizabeth Warren has major challenges too — she hasn’t done much better than Biden (third in Iowa and fourth in New Hampshire), and doesn’t have some of the potential advantages that the former vice president still has. Warren’s most obvious problem is that she’s being crowded out in the demographic and ideological voting groups she’s best positioned to do well in.

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Back at the start of this campaign, if you thought Warren might win the nomination, you would have expected her to win at least one of four groups: voters who identify as very liberal, voters who identify as somewhat liberal, women and college graduates. That seemed possible at one point: Through much of October and November, it looked like Warren had dislodged Sen. Bernie Sanders from the top spot among the party’s left-wing voters, for example.

It hasn’t happened. In both Iowa and New Hampshire, she finished well behind Sanders among self-identified very liberal voters, according to entrance and exit polls. Pete Buttigieg and Sanders ran ahead of her among somewhat liberal voters in both states, as did Sen. Amy Klobuchar in New Hampshire. Warren finished third in Iowa and fourth in New Hampshire among women. Among college graduates, she finished second in Iowa (to Buttigieg) and fourth in New Hampshire.

And in both states, she finished far behind among voters who identify as moderate, trailing Sanders, Buttigieg, Klobuchar and Biden.

The Warren campaign recognizes all of this, of course. So in what may simply be a concession to the reality she faces, the Massachusetts senator has as of late been casting herself as the candidate who can unify the various wings of the Democratic Party rather than trying to directly take on Sanders, who is running an unabashedly liberal campaign and had a four-year head start on Warren in cornering the liberal wing of the party from his previous presidential run.

But Warren’s pivot to a message of unity isn’t working either. At least based on the results in the first two states, Buttigieg, not Warren, seems more able to draw support from disparate parts of the party. The former South Bend mayor is winning more than 20 percent of voters under 45, over 45, liberals, moderates, college graduates and voters without a degree — a notable achievement in a race where few candidates are getting into the 20s overall or with any blocs. National polls and recent surveys of upcoming states show similar dynamics: Sanders generally leads among younger and more liberal voters, with Warren trailing him among those groups and trailing several other candidates among more moderate and older voters.

Of course, this is all a lot of data saying the same thing: Warren doesn’t have a ton of support overall. Warren finished with just 9 percent of the vote in New Hampshire and has 13 percent in our average of national polls. With those numbers, you’re naturally going to struggle with lots of groups. Conversely, when Warren edged into the low- to mid-20s in national polls last year, not only was she doing better with her core groups, but she was even starting to make inroads with moderate and nonwhite voters.

Which is all to say that we shouldn’t count Warren out. She’s fought her way back from low-polling numbers before — in this same campaign! But Warren does have some new obstacles this time around.

First, finishing fourth in New Hampshire has the potential to create a self-reinforcing negative cycle for Warren. Early primaries are as much about buzz, perception and media coverage as they are about pledged delegates. A candidate will receive more favorable media coverage, endorsements from other elected officials and campaign donations after a surprisingly strong performance in an early state. Good news can beget more good news. Warren is facing the opposite possibility — a cycle of negative buzz and/or non-coverage.

On Tuesday afternoon, before voting was over in New Hampshire, Warren campaign manager Roger Lau published a post on Medium that effectively served as a preemptive strike against just such a negative feedback loop. He argued that only Biden, Sanders and Warren have the campaign organizations and support broad enough to accumulate the delegates necessary to win the nomination. But a memo can’t really nullify a fourth-place finish in a state that partially shares a media market with the one Warren has represented in the Senate for years. I suspect Democratic Party insiders will start asking if Warren can’t win — or even finish in third in New Hampshire — where can she win? (Admittedly, in asking that question in a prominent news outlet, I’m perhaps creating or perpetuating just the kind of negative news cycle I’ve described.)

Warren’s second big problem is that there is little evidence that she’ll do better once the primary moves beyond the first two, mostly white states. Her poll numbers among black and Latino voters are weak (although better than Buttigieg’s). This is in contrast to Biden, whose advantage among voters of color may have been diminished by his dismal showings in the first two states but who has at least shown the clear potential to attract support from nonwhite voters.

Finally, there’s Sanders. He’s in a much stronger position now than when Warren first rose in the polls throughout the second half of last year. Sanders may be able to start consolidating support among left-wing voters. (The same is true for Klobuchar, by the way, with whom Warren now has to compete for college-educated women in particular.)

The moderate lane is complicated: Buttigieg did well in Iowa and New Hampshire but may be weak in states with lots of black and Latino voters; Biden did terribly in the first two states, but many in the party are deeply invested in the former vice president both because they have already endorsed him and because they believe he is the party’s best chance to defeat President Trump in a general election; former New York City Mayor Michael Bloomberg is rising in national polls and endorsements but he hasn’t actually competed in a state yet; Klobuchar is likely to get some more buzz and money from her strong showing in New Hampshire, but it’s not clear she has either the support among black or Latino voters or the campaign organization to succeed in future states.

If Warren struggles in Nevada and South Carolina, I expect to see liberal figures in the party, even those who personally like the Massachusetts senator, to start urging her to leave the race. A Warren departure would give the party’s liberal activists a chance to unify behind Sanders, push all liberal voters to back him and try to prevent a more centrist candidate from winning the primary.

Again, don’t write off Warren. She could pull off a surprisingly strong finish in Nevada or even win the state, where we have little polling and none of the candidates have an obvious advantage. Buttigieg’s weakness among black and Latino voters provides an opportunity for the other candidates, including Warren — perhaps she can actualize the “unity” message better once the race moves to more diverse states.

More broadly, Warren’s problem right now also has the potential to be an advantage, particularly if the race winnows down and she’s one of the remaining candidates. Her positioning makes her broadly acceptable to different wings in the Democratic Party — she’s to the right of Sanders and to the left of Biden, Bloomberg and Buttigieg. But at the moment, being everyone’s second choice isn’t worth much; it’s just another way of saying that you’re few people’s first choice. It’s the Marco Rubio problem. But this nomination race is incredibly unsettled, and at some point, having wide appeal might come in handy.

Or not.