Kamala Harris slides in 2020 Democratic presidential primary polls

Through all of the 2020 Democratic presidential primary’s early ups and downs, Joe Biden has consistently outpaced the field in polls.

The former vice president has led nearly every survey at both the national and early nominating state level. His support dipped following the first Democratic debate in late June, then stabilized in recent weeks.

Biden has so far shown staying power at the top of a jammed Democratic field even as his rivals’ polling numbers wax and wane. Sen. Kamala Harris, D-Calif., has seen her standing change most dramatically: she surged from fourth to second in the RealClearPolitics national polling average after a strong first debate showing, then dropped back to fourth.

Surveys can only say so much this early in the race, as a lot can happen between now and the first nominating contests in February. Even so, the polls offer a snapshot of where the race stands now and how it has changed. Support for Harris has flagged, while neither Sen. Elizabeth Warren, D-Mass., or Sen. Bernie Sanders, I-Vt., have pushed their way into a clear second-place position.

State polls are perhaps a better gauge of who could win the nomination, as no primary voting will actually take place at the national level.

Here is the latest RealClearPolitics average of recent national polls:

• Biden: 29% (-3 since Aug. 1)
• Warren: 15.8% (+1 since Aug. 1)
• Sanders: 15.4% (-1 since Aug. 1)
• Harris: 7.4% (-3.6 since Aug. 1)
• South Bend, Indiana, Mayor Pete Buttigieg: 4.6% (-1 since Aug. 1)
• Former Rep. Beto O’Rourke: 3.4% (+0.4 since Aug. 1)
• Sen. Cory Booker, D-N.J.: 2.2% (+0.6 since Aug. 1)
• Entrepreneur Andrew Yang: 2% (+0.4 since Aug. 1)
• Rep. Tulsi Gabbard, D-Hawaii: 1.4% (+0.4 since Aug. 1)
• Former Housing and Urban Development Secretary Julian Castro: 1.4% (+0.4 since Aug. 1)

Biden also has enjoyed a consistent edge in polling in the states that hold the earliest nominating contests: Iowa (Feb. 3), New Hampshire (Feb. 11), Nevada (Feb. 22) and South Carolina (Feb. 29). His lead in those states is smaller than his advantage nationwide, especially in New Hampshire, which borders the home states of both Sanders, who won the state’s primary in 2016, and Warren.

Here are the RealClearPolitics polling averages in those early voting states:

Subscribe to CNBC on YouTube.