FAIRFIELD, Iowa — Sen. Cory Booker seemed primed to take off in the Democratic primaries: He's a black senator with bipartisan accomplishments, a Rhodes Scholar, a three-time former mayor of Newark, and a charismatic speaker with well over a decade of favorable media coverage under his belt.

Yet Booker is mired in the low single-digits in early Democratic primary polls, crowded out in a 23-strong Democratic field with political novices eclipsing him.

A dismal Monmouth University poll released last week found that the New Jersey senator had 1% support nationally among Democratic primary voters, down from 5% in March, placing him among more obscure candidates such as eccentric businessman Andrew Yang and self-styled spiritual guru Marianne Williamson.

For much of his political career, Booker, 50, has been a rising star. In 2012, talk show host Jon Stewart called Booker a “superhero mayor,” and Oprah Winfrey raised money for his 2013 special Senate election. The media repeatedly compared him to Barack Obama. On the campaign trail, Booker touts the 2005 documentary that helped him gain notoriety, “Street Fight,” an Oscar-nominated film about his first failed mayoral bid.

But Booker’s celebrity has worn off, and younger, fresher candidates with similar attributes - and some extra positives - dominate the conversation.

Pete Buttigieg, 37, has made being mayor of South Bend, Ind., a central selling point of his campaign, is also a Rhodes Scholar. Giving him a boost against Booker is his lack of Senate experience - being a Washington outsider is more appealing. He is also an Afghanistan veteran. While Booker is single and has always been reticent about his private life, Buttigieg is an openly gay man whose husband is front and center in his White House bid.

Former Texas Rep. Beto O’Rourke, 46, dominated in fundraising after gaining national attention during his failed 2018 Senate bid. Voters hoping to see a woman as the Democratic nominee are turning towards Sen. Kamala Harris, D-Calif., 54, who, like Booker, is black and vying for the African American vote.

“There are many cars driving through certain political lanes, and I think that is causing havoc on the political highway,” South Carolina-based Democratic strategist Antjuan Seawright told the Washington Examiner. Booker just needs to find his niche, Seawright said.

Booker is outwardly unfazed by the early poll, and he has a plan to become a star again. “The national polls this far out mean nothing,” he told reporters in Fairfield on Friday. “I just know we’re doing extraordinarily well according to what’s important to us,” citing attendees at an event signing commitment-to-caucus cards, his early endorsements, and his large campaign team.

Booker has almost 50 full-time staffers in Iowa, an infrastructure in the state second only to that of Sen. Elizabeth Warren, D-Mass., according to the Booker campaign. In New Hampshire, his campaign has three offices, more than any of the other presidential candidates.

[ Opinion: Cory Booker 2020 has been a bust]

The organization was on display in Fairfield, when a stop scheduled to be a house party moved to a senior center due to interest. About 100 people attended the standing-room only event. A few days later, 500 people were at a Booker Memorial Day barbecue in Urbandale, the campaign said.

If anything, however, his campaign organization and structure make his low poll numbers even more ominous - his candidacy is being marketed efficiently but only a small number of supporters are buying it.

New Hampshire political strategist and Booker adviser James Demers, an early Obama supporter in 2008 cycle, said Booker may yet break through.

“That first debate in June is going to be very important,” Demers told the Washington Examiner at a campaign stop in Keene, N.H., earlier this month. “That’s where some of the lesser-known candidates are going to get, obviously, better-known, and one or two of them could end up being a star at those debates and really skyrocket.”

Until then, Booker is clinging on. “The name of this game with an overcrowded primary is sustainability,” Seawright said. “Cory is the type of candidate that you can never count out.”