(Tom Toles/The Washington Post)

I’m Greg Sargent, and this is Round 29.

The Commentary

Remember how we all declared that Kamala D. Harris was surging and had suddenly demonstrated her fitness to take on President Trump when she disemboweled Joe Biden at the Democratic debate in June?

Well, suddenly she’s “fading.”

A new CNN poll finds that among Democrats nationally, Harris has dropped an astonishing 12 points, from 17 percent to 5 percent, putting her around where she was before that debate. Other recent polls have her in single digits, too. The resulting chatter is that she is disappearing.

But remember how Biden’s campaign was said to be in crisis after Harris throttled him? Now Biden is moving up again — unfading, if you will. That’s because we’re still early enough that candidates with enough solid support can bob up and down without dire consequence.

Resultantly, the whole “electability” thing we keep arguing over is equally ephemeral. As political scientists point out, the perceptions of candidates’ viability in a general election sometimes improve when their support among primary voters rises. People think the candidate they like is electable, or, alternatively, people think the candidate who has gained support at any given moment is electable. How’s that for a surprise?

This happened with Harris when she rose in polls after her confrontation with Biden. Now, you can bet that perceptions of her general-election viability will fade as her support deflates. As for Biden, he has been busy citing polls showing that Democrats see him as the best to take on Trump. See how that lasts.

Maybe even Andrew Yang will seem electable before we know it. Despite being an entrepreneur with no government experience, Yang is doing better in some polls than a senator (Amy Klobuchar) or a former federal agency chief (Julián Castro), and he has qualified for next month’s debate.

To be clear, it’s a salutary thing that Yang is, for now, surpassing expectations. It’s a real positive that the candidacy all about universal basic income is (1) being waged at all and (2) doing well relative to expectations — “surging,” even, according to a recent Politico profile.

But surging, as fading, is fleeting.

— Greg Sargent

The Ranking

Ranking not showing? Click here.

Position Challenger Change Over Last Ranking
1. Elizabeth Warren UP 1
2. Joe Biden DOWN 1
3. Bernie Sanders UP 1
4. Kamala D. Harris DOWN 1
5. Pete Buttigieg
6. Cory Booker
7. Beto O’Rourke
8. Amy Klobuchar
9. Julián Castro
10. Andrew Yang
11. Tom Steyer
12. Steve Bullock
13. Michael Bennet UP 1
14. Tulsi Gabbard RETURNS TO RANKING
15. (TIE) Kirsten Gillibrand RETURNS TO RANKING
15. (TIE) Marianne Williamson RETURNS TO RANKING

Falls off ranking: Seth Moulton, Tim Ryan

Last week’s ranking: Round 28 | Here’s some perversely good news for the 2020 Democrats

Don’t forget to click on the yellow highlighted text above to expand the Ranking Committee’s annotations. Agree? Disagree? Share your thoughts in the comments. We’ll see you for the next ranking. Until then, surge on.

Read more on 2020:

Henry Olsen: Most Democrats won’t be able to break out of the pack. Jay Inslee is proof.

Greg Sargent: The Trump campaign is worried about suburban women. For good reason.

Jennifer Rubin: Joe Walsh might be just the guy to take on Trump