WASHINGTON — Cory Booker will be on stage Wednesday night with nine other Democrats for the fifth presidential debate.

It may be his last appearance.

Booker hasn’t met any of the thresholds for qualifying for December’s debate in Los Angeles. He and entrepreneur Andrew Yang are the only Democrats in the first five debates who have yet to qualify for No. 6, according to the Washington Post.

Six candidates — Joe Biden, Pete Buttigieg, Kamala Harris, Amy Klobuchar, Bernie Sanders and Elizabeth Warren — have won a spot on the debate stage in December, as they have for the all of the other debates.

“The debate is where everybody looks for that next candidate to break out,” said Rep. Donald Norcross, D-1st Dist., who has endorsed Booker. “The idea of not being on that stage is difficult.”

Yang is close to qualifying for the December debate. He has met the requirement of having 200,000 unique donors and has received at least 4 percent in three of the four surveys he needs to qualify, according to the Post. (A candidate also can qualify with 6 percent in two early-state polls.)

Booker has done none of that, though he said in a fundraising email on Tuesday that he was less than 15,000 contributors away from meeting the donor requirement.

Three recent polls didn’t help Booker’s case. On Wednesday, a St. Anselm College poll of likely New Hampshire Democratic primary voters gave Booker 3 percent. A Quinnipiac University poll released Monday put him at 2 percent in South Carolina, a state where a majority of Democratic primary voters are black. Over the weekend, the Des Moines Register/CNN/Mediacom Iowa poll gave him 3 percent in the first caucus state. He has not gotten 4 percent in any poll that counts for the next debate.

While Booker won plaudits for his earlier debate performances, they never translated into a breakthrough moment.

With so many candidates on stage, he may never get one, said Ben Dworkin, director of Rowan University’s Institute for Public Policy and Citizenship.

“I don’t think the debates mean anything when you have that many people on stage,” Dworkin said. “Even if Booker misses the debate, I’m not sure how much that affects anything beyond the chattering class. These debates have not been particularly illuminating."

Still, Deputy Campaign Manager Jenna Lowenstein said In a recent fundraising email that qualifying for the December debate was important to Booker’s campaign.

“If we don’t meet the qualifying thresholds for the December debate, then Cory’s voice will be left out of the conversation,” she wrote to supporters. “Every time he’s on that stage, more people get to know him and more people learn how critical it is to have his voice part of this conversation. It’s up to us to make sure the November debate isn’t his last.”

Norcross said it is too early to count Booker out.

“One thing that we’ve seen time after time with the senator is just when you think he’s not going to make it, he comes through,” Norcross said.

Wednesday’s debate features 10 candidates: Biden, Booker, Buttigieg, U.S. Rep. Tulsi Gabbard, D-Hawaii, Harris, Klobuchar, Sanders, businessman Tom Steyer, Warren and Yang.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.

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