Sen. Elizabeth Warren (D-MA) participates in a reenacted swearing-in with then-Vice President Joe Biden in the Old Senate Chamber at the US Capitol January 3, 2013, in Washington, DC.

Last week’s second Democratic debate did little to change the race — Joe Biden, Bernie Sanders, and Elizabeth Warren continue to be the top candidates, per new post-debate polls.

National polls from Quinnipiac, HarrisX, Reuters/Ipsos, and Politico/Morning Consult — and a New Hampshire poll from the Boston Globe/Suffolk — all show Biden in first place, with somewhere between 21 and 33 percent of the vote.

Four of those polls show Sanders in second place and Warren in third — however, one of the national polls, from Quinnipiac, showed Warren ahead of Sanders in second place.

Meanwhile, Kamala Harris appears to have declined from her significant bounce in the polls in late June following a tense exchange with Biden on busing in that first debate. Back then, she went from a distant fourth to, essentially, tied for second place with Sanders and Warren. But now she tends to poll closer to fifth-place Pete Buttigieg than to the top three contenders.

A HuffPost/YouGov poll asking Democratic and Democratic-leaning voters whether their opinion of each candidate improved or worsened from the debate showed Harris as the only top-tier candidate whose image suffered on net.

Warren: 50 percent improved, 6 percent worsened

Buttigieg: 32 percent improved, 8 percent worsened

Sanders: 28 percent improved, 16 percent worsened

Biden: 26 percent improved, 24 percent worsened

Harris: 25 percent improved, 30 percent worsened

Now the Politico/Morning Consult poll shows Harris in fourth place with 9 percent, and the Quinnipiac poll shows her in fourth with 7 percent (among national Democrats, in both cases). Other national polls have shown similar results. The Boston/Globe Suffolk poll of New Hampshire has Harris in fourth there, too, with 8 percent.

Biden, meanwhile, had declined a bit in national polls after the first debate, feeding questions about whether his support was shaky. But he remained in first place throughout, and even before the second debate, he’d recovered. The debate itself has done nothing to change that: The former vice president remains the man to beat.

Nobody else broke out

Beyond the top tier (broadly defined) of Biden, Sanders, Warren, Harris, and Buttigieg, there were of course 15 other candidates onstage last week.

Some commentators declared Marianne Williamson had a breakout performance; some thought Cory Booker deserved a bounce; some believed John Delaney’s centrality on the first night would be good for him.

The HuffPost/YouGov poll that asked Democrats whether their opinion of each candidate improved or worsened showed a strong net improvement for Booker (20 percent net improvement) and Julián Castro (17 percent net improvement).

But when it came to whom Democrats would vote for, Booker, Castro, and the other bottom-tier candidates are all still polling at 3 percent or below in all the post-debate polls.

The next debate isn’t until September. But the threshold for qualifying for that one is higher — a candidate needs to hit 2 percent in four recent polls from approved organizations, and to have at least 130,000 donors.

Currently, only eight candidates say they’ve met that threshold: Biden, Sanders, Warren, Harris, Buttigieg, Booker, Beto O’Rourke, and Amy Klobuchar. A few more may make the cut too, but several will surely miss it — and with no future national platform likely, they may decide to bring their campaigns to an end.