CNN  — 

Former Vice President Joe Biden has bounced back to where he was before the first Democratic debate in early July, with 34% support among Democrats and Democratic-leaning independent voters in a new Quinnipiac poll.

The new poll, released a day before the second round of Democratic primary debates in Detroit, shows Massachusetts Sen. Elizabeth Warren follows Biden with 15% support, California Sen. Kamala Harris with 12%, Vermont Sen. Bernie Sanders at 11%, and South Bend, Indiana, Mayor Pete Buttigieg at 6%. The difference between Warren, Sanders and Harris is within the poll’s margin of error, while Biden leads the group.

The biggest mover since the last Quinnipiac poll is Harris, who dropped 8 percentage points in her support in a poll taken in the wake of the first debate. Before that debate, Quinnipiac had Biden at 30% and Harris at 7% – and immediately after Biden was at 22% and Harris at 20%.

This poll finds much different numbers than the previous survey, with Harris losing some (but not all) of the support she saw in her surge following the first round of debates. Sanders also lost 8 percentage points since June, having gotten no bump from debates. Warren maintained her 15% support; she’s had between 12% and 15% support since April.

Polls taken directly after debates tend to show a surge in support for some candidates who become more prominent in the minds of voters after the performance. Harris made waves at the second night of the first debates, calling out Biden on his past policy choices.

It is more rare for candidates to remain stable, with only one who is polling above 5% not showing significant movement in the wake of the debates: Warren. Sanders has been steady since the debates, but saw some movement since June.

The second round of debates is hosted by CNN Tuesday and Wednesday in Detroit, and could shake up the order of the top five candidates even more. It remains to be seen if any candidate can make that surge in support stick beyond a post-debate bump.

Warren performs better among Democratic voters who consider themselves very liberal (29%) than somewhat liberal (14%) or moderate/conservative (9%). Sanders is in a similar boat – 15% of his supporters are very liberal, 16% somewhat and only 8% are moderate/conservative.

Meanwhile, Biden’s supporters tend to be moderate/conservative (39%), instead of somewhat liberal (34%) or very liberal (25%). Harris’ support is divided relatively evenly: 12% very liberal, 10% somewhat liberal and 12% moderate or conservative.

Biden continues to top among Democratic black voters, with 53% who plan to support the former vice president. That’s compared to 8% for Sanders and 7% for Harris.

Older voters are also more interested in Biden than other groups (47% of those over 65 years old, 34% of those 50-64, and 27% under 50). Sanders sees the biggest gap for young voters (18% of those under 50, 7% 50-64-year-olds, and 3% of those over 65).

Biden tops other candidates in terms of who Democrats said would be the best leader (36%), bouncing back from only 26% who said so after the first round of debates, and 44% who said so in April. He is followed by 17% for Warren, 12% for Sanders, 9% for Harris and 5% for Buttigieg.

Biden has also seen a jump in the percentage of people who think he can beat President Donald Trump in the general election (51% now, up from 42% in July, and 56% in April). One in 10 said the same of Sanders, 8% for Harris and 8% for Warren.

The only category where Biden doesn’t lead is who Democratic voters think has the best policy ideas, where Warren is on top, with 26% who said so over 21% for Biden. Sixteen percent thought Sanders has the best policy ideas, 6% for Harris and 5% for Buttigieg.

Trump’s approval among registered voters remains steady, with 40% of voters who approve, 54% who disapprove.