Several post-debate polls conducted after the first Democratic debate show former Vice President Joe Biden and Sen. Bernie Sanders stalling or losing support, with Sens. Kamala Harris and Elizabeth Warren making gains among primary voters.

A CNN poll published Monday found Biden with 22% support among registered Democrats and Democratic-leaning independents nationwide, a drop of 10 percentage points since the previous CNN poll in May. Harris was close behind with 17% and Warren 15%, an increase of 9 and 8 points respectively. Sanders garnered 14% support, a drop of eight percentage points.

In the CNN poll, South Bend, Indiana, Mayor Pete Buttigieg received 4% support, Sen. Cory Booker and former Rep. Beto O'Rourke garnered 3%. Sen. Amy Klobuchar remained steady with 2% support.

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A Tuesday Suffolk University/USA Today poll of Iowa Democratic voters who say they are likely to attend the state's caucuses also saw Sanders in fourth place behind Biden, Warren and Harris. Biden garnered support from 24% of respondents, which was no change from a Des Moines Register poll in the state last month. Harris received 16% support in the USA Today poll, with Warren 13% and Sanders 9%.

A national Quinnipiac University poll of Democrats and Democratic-leaning voters released Tuesday found Biden and Harris virtually tied, with Biden earning 22% support and Harris receiving 20%. Warren followed at 14%, and Sanders at 13%. Biden's support dropped by 8 points since the previous Quinnipiac poll, and Sanders lost 6 points. Harris gained 13 points and Warren's support dipped by a point.

The CNN poll had a margin of error of plus or minus 4.7 percentage points. The margin of error for the USA Today poll was 4.4 percentage points, and Quinnipiac had a margin of error of 5 points.

Meanwhile, a Univision poll published Tuesday of Latino voters eligible to vote in the Democratic primaries nationwide showed Harris in the lead with 22% support, and former HUD Secretary Julián Castro at 18%. Biden and Sanders were each at 16%, and Warren at 9%. Castro appeared at the first debate on Wednesday. The Univision poll had a margin of error of 4.8 percentage points.

Warren appeared in the first round of the debate last Wednesday and reasserted her message of implementing structural change. Biden, Harris and Sanders appeared on the second night of the debate on Thursday, where Biden was bruised by a clash with Harris, who challenged the former vice president on his relationships with segregationist senators and his views on busing.

Harris's campaign announced on Saturday that she had raised $2 million in the first 24 hours following the start of Thursday's debate.