The Democratic presidential contest has gotten closer after the first debate — though pollsters differ on just how much closer it’s gotten.

A new poll from CNN/SSRS found that former Vice President Joe Biden remains in first place, with the support of 22 percent of national Democrats or Democratic-leaning independent voters. But three candidates are nipping at his heels: Sen. Kamala Harris has 17 percent, Sen. Elizabeth Warren has 15 percent, and Sen. Bernie Sanders has 14 percent.

That’s Biden’s smallest lead in months and Harris’s best showing all year. And it seems to reflect the conventional wisdom after the first debate wrapped up Thursday night — that Harris was the breakout winner and had done some real damage with her attacks on Biden over his opposition to federally mandated desegregation busing in the 1970s.

Other polls, however, have shown a less dramatic impact. Morning Consult’s post-debate findings showed movement in the same direction — Biden losing some support and Harris gaining — but they still found Biden ahead by double digits and Sanders in second. So whether Biden is collapsing or whether his lead has just slipped a tad isn’t yet clear.

But the general direction of CNN’s findings does seem to match what other pollsters have found. For instance, a HuffPost/YouGov poll found that Harris’s image improved dramatically among Democratic and Democratic-leaning voters, while Biden’s worsened overall.

Interestingly, CNN’s poll showed Biden continuing to lead among black voters, with 36 percent support compared to Harris’s 24 percent. But that’s an improvement from how Harris had been doing previously. And it’s worth remembering that even as late as October 2007, polls showed Hillary Clinton was still trouncing Barack Obama among black voters — a state of affairs that changed dramatically after Obama won Iowa.

The poll is also noteworthy because generally, Sanders has tended to poll in second place — and here, both Harris and Warren have around the same amount of support as him (indeed, they’re slightly ahead of him, though the difference is within the poll’s margin of error). Meanwhile, South Bend, Indiana, Mayor Pete Buttigieg is also down at 4 percent — still in fifth place, but now with a support level more comparable to a lower tier of candidates.

Does the frontrunner have a glass jaw?

All year, Biden has led in the vast majority of national and early-state polls of Democratic voters. One obvious way the nomination process could play out is that the longtime frontrunner just, well, wins.

But another possibility has been that once voters get a closer look at Biden on the campaign trail and on the debate stages, he won’t fare so well — and that some of his 24 rivals might seem more impressive.

Already, Biden’s poll lead was far less commanding than Clinton’s ever was in 2016 (or 2008). Some Democratic insiders have long had doubts that he’d be a good fit to lead the present-day version of the party — both because he may be out of touch with the current Democratic electorate and because he has a tendency to make verbal gaffes.

What’s been less clear is who would pose a serious challenge to Biden. Sanders, the 2016 runner-up, was of course one possibility, and has polled in second place for most of the year. But mainstream Democrats searching for new leadership do not seem to have been particularly drawn to the anti-establishment Sanders campaign — currently, he’s underperforming his 2016 level of support in a more crowded field.

Before the debate, however, Elizabeth Warren had started to gain ground in polls. And after it, she has been joined by Harris in the top tier of candidates. Both now seem to be viable options for Democrats searching for a non-Biden, non-Bernie alternative.

There’s still of course ample time for Biden to turn things around — the Iowa caucuses are seven months away. But a poll like this certainly isn’t good news for a frontrunner who had serious weaknesses all along.