Given the time to register to vote in advance of the caucus and primary season, these results are among all leaned Democrats. Among those who are registered now, Biden goes to a 30-19 percent advantage over Sanders, with 13 percent for Harris and 12 percent for Warren. Crosscurrents underlie candidate preferences in this poll, produced for ABC by Langer Research Associates. A broad plurality, 45 percent, says Biden has the best chance to beat Donald Trump in the general election, but only 18 percent say he has new ideas, trailing Sanders, Warren and Harris alike. At the same time, 41 percent say Harris stood out in her debate performance, easily the leader in this gauge, a wide 15 to 22 percentage points ahead of Biden, Sanders and Warren. And among those who actually watched both Democratic debates last week, the number picking Harris as a standout performer soars to 72 percent, well above any of her competitors.

An impact is apparent: Among the half of leaned Democrats who did not watch either of the two nights of debates, just 5 percent support Harris for the nomination. Among those who watched the debate in which she appeared, by contrast, her support swells to 20 percent. That places her numerically second among Thursday-night viewers; Biden has 28 percent support in this group; Warren, 17 percent; and Sanders, 15 percent. Warren also does better among viewers of her debate than non-viewers, 17 vs. 8 percent support. Showing strength among highly engaged leaned Democrats, she reaches 22 percent, virtually matching Biden’s 25 percent, among those who watched both debates. There’s no meaningful difference in Biden’s support across debate-watching groups, and Sanders gets the booby prize – higher support among those who did not watch the debates, 26 percent, vs. 15 percent among those who watched the debate in which he appeared and 10 percent among those who watched both nights. Comparative inattention fits with his younger support profile; 18- to 29-year-olds, his best group, are least likely to have tuned in.

These results are from a question in which respondents were read a list of Democratic candidates. Asking preferences in an open-ended format produces similar results (25-18-9-9 percent, Biden-Sanders-Harris-Warren), with gains for each in comparison with April – Biden +8 points, Sanders +7, and Harris and Warren both +5. Those with no opinion dropped sharply, 35 percent in April compared with 19 percent now (and 6 percent when the full list is read). In another measure, intended participation is high: Seventy-two percent of leaned Democrats say they’re certain to vote in their state’s primary or caucus. That’s up from 56 percent in November 2015, when it was first asked in the last cycle, a race that pitted just two prime candidates. Current results are similar to what they were in November 2007, the last crowded (albeit not this crowded) Democratic race.

DEBATE REAX

Harris’ debate rating comes among those who actually tuned in. Respondents were asked which candidates stood out as having done an especially good job in the debates, with up to four names accepted. Among those who watched both nights, a vast 72 percent picked Harris for a standout performance. Fewer but 58 percent named Warren. Neither Biden nor Sanders, nor others, remotely approach these levels. (Pete Buttigieg comes closest, cited by 31 percent.)

GROUPS

Notably among groups, while Harris challenged Biden on the subject of race in their debate, his support is especially strong among blacks, 41 percent, 12 points higher than it is overall. Harris’ support, by contrast, is not differentiated by race and ethnicity – 11 percent among blacks and an identical 11 percent among all leaned Democrats. Warren, for her part, has notably low support among nonwhites, 5 percent. Biden’s support continues to skew older, Sanders’ younger: Among leaned Democrats age 50 and older, Biden leads Sanders by a broad 39-11 percent. Among those younger than 50, Biden’s support falls to 21 percent and Sanders’ rises to 32 percent. (There are no such age gaps in support for Warren or Harris.)

Among other group differences, Sanders’ support plummets among the most-educated group, while Warren’s rises with education. And by ideology, Warren does better with liberals compared with moderates. (Biden’s better number among moderates than liberals isn’t statistically significant.)

While the contest pits prominent Democratic women and men alike, there are no substantial differences in candidate choice on the basis of gender. Men divide 26-26-10-9 percent among Biden-Sanders-Harris-Warren; women, by a similar 30-21-12-13 percent.

WHO ELSE?

Former Vice President Biden and 2016 candidate Sanders are, of course, the best-known figures in the Democratic race. While they’re in front, it’s striking that most Democrats and Democratic leaners are not entirely wedded to their current choices; just about a quarter, 26 percent, say it’s “extremely” important to them that their candidate wins the nomination. That includes about the same number just among Biden’s supporters, 29 percent.

Still, asking second-choice preferences finds another advantage for Biden: Among those who don’t support him now, 33 percent pick him as their next-choice candidate. By comparison, among those who don’t currently favor Sanders he’s second choice for 24 percent. Warren is second choice for 17 percent of those who don’t back her now, as is Harris for 16 percent.

That said, another Biden advantage – being seen as the candidate best able to defeat Trump – is unlikely to be all it will take for Biden to prevail. It’s notable that, among those who pick Biden on this measure, 45 percent nonetheless support another Democratic candidate.

ISSUES

Health care is the top-rated issue for Democrats and Democratic leaners, and they side heavily with a so-called Medicare-for-all system, a central topic of the debates. Seventy-seven percent of leaned Democrats support a government-run, taxpayer-funded universal health care system like Medicare, essentially the same as in an ABC/Post poll back in 2003. Support remains high, 66 percent, even if it meant doing away with private insurance. Health care, moreover, is cited by 89 percent of leaned Democrats as a top issue in their vote in the general election, leading a list of nine items.

Eighty-five to 79 percent cite gun violence, issues of special concern to women, immigration, global warming and the economy as highly important, followed by foreign policy, 72 percent; abortion, 69 percent; and taxes, 60 percent. Preference in handling two of these issues is generally similar to candidate support overall.

On health care, 27 percent of leaned Democrats pick Sanders as the candidate they trust most and 25 percent pick Biden, followed by 13 percent for Warren and 7 percent for Harris. On immigration, another focus of the debate, 21 percent pick Biden; 17 percent, Sanders; 12 percent, Harris; and 8 percent Warren, with an additional 8 percent favoring Julián Castro.

Viewed another way, Biden and Sanders are essentially tied among leaned Democrats who focus on any of five top issues – health care, issues of special concern to women, immigration, global warming and the economy. One remaining item differentiates them – gun violence, on which Biden has a 10-point advantage. Warren and Harris compete for third position on all these.

While most issue preferences don’t sharply differentiate candidate choices, there are some differences in issue emphasis among groups. The economy, for example, is rated as highly important by 85 percent of those without a college degree vs. 67 percent of college graduates, and by 84 percent of those with less than $50,000 in annual household incomes vs. 70 percent of those in the $100,000-plus bracket.

GENDER