Tuesday was the big moment that Hillary Clinton has been waiting for: Bernie Sanders, who gave her a hard, unexpected fight for the Democratic nomination, endorsed her.
Their appearance together in New Hampshire was a show of party unity, but voter unity may be harder to achieve — especially among young voters. A new poll from The Associated Press and University of Chicago suggests Clinton has yet to convince this group, perhaps Sanders' most reliable demographic this campaign season. Her weakness extends across racial and ethnic groups.
There's a little good news for Clinton in the poll of 18- to 30-year-olds — in a matchup against Donald Trump, she clearly bests the New York businessman, 38 to 17 percent. But that leaves 45 percent of those young adults who said they were either undecided, wouldn't vote or would vote for someone else (22 percent).
Another stat that bodes poorly for Clinton: Those who chose her aren't exactly crazy about her — many instead simply dislike Trump. Those who chose Clinton are about evenly split: 47 percent said they "mainly support" her, while 53 percent said they "mainly oppose" Trump.
Sanders inspires more enthusiasm. In a Sanders-Trump matchup, 61 percent of young adults chose Sanders, compared with only 16 percent who chose Trump. In this scenario, the share of people who would choose "someone else" is drastically smaller: 7 percent, compared with 22 percent in the Clinton-Trump matchup. In addition, nearly three-quarters of those who would choose Sanders said it's because they support him (as opposed to opposing Trump).
Interestingly, views of Sanders are more consistent across ethnic groups compared with views of Clinton. Young black voters are most likely to see Clinton favorably, at 64 percent. Among young, non-Hispanic white voters, it's only 26 percent — the smallest share of the four ethnic groups studied.
Meanwhile, 55 percent of whites view Sanders favorably, and the share is more than 70 percent among Asian-Americans, Latinos and African-Americans.
The survey, from the Black Youth Project at the University of Chicago with the AP-NORC Center for Public Affairs Research, interviewed nearly 2,000 adults between the ages of 18 and 30, including enough black, Hispanic and Asian-Americans for those groups' results to be statistically significant. Results from the full sample have a margin of error of +/- 3.8 percentage points.
The results echo the results of the Democratic primaries, in which Sanders regularly — and often dramatically — beat out Clinton among young voters in exit polls.
One important point about this poll, however: It was conducted in mid- to late June. Since then, there have been a few shifts in the Democratic storyline. For example, at the end of this survey's interview period, on June 24, Sanders said he would vote for Clinton. And since then, Clinton has also embraced one of Sanders' best-known ideas (one that happens to appeal to young people): providing free tuition at public colleges and universities. She has also reworked her health care proposals to look more like Sanders', as NPR's Tamara Keith wrote this week.
And today came the big moment: the Sanders endorsement.
His blessing may swing a few more Sanders stalwarts into the Clinton column and further shore up her support. Currently, in Trump-Clinton polling matchups, the two major-party candidates together regularly get the support of only around 80 percent of registered voters.
It's possible that the Sanders endorsement could help Clinton get part of that remaining 20 percent. Sanders inspires fierce loyalty among his supporters, and some may follow him into the Clinton camp. Still, many may simply refuse to let go of his candidacy, and others believe a Sanders endorsement would be a betrayal of progressive principles. Pro-Sanders forums on Reddit, for example, give a taste of just what some are feeling:
Young voters were key to helping Obama win both of his presidential elections. Obama bested Romney 60 to 37 percent among 18- to 29-year-olds in 2012, and he beat McCain 66 to 32 among this group.
However, putting all her emphasis on the youth vote wouldn't make much sense, either; young voters never have nearly as high a voting rate as their older counterparts.
This post was updated on July 12, 2016, at 2:18 PM.