Nonetheless, Mr. Booker seemed to confound supporters, donors and pundits who remained mystified about why he never had his “moment” during the primary. He started his campaign with a limited base of online donors and a heavy reliance on traditional big-dollar fund-raisers. Without ever experiencing the kind of surge in support that could have led to a surge in online fund-raising, Mr. Booker was forced to run a shoestring campaign, unable to finance the frequent television advertising that has helped candidates like Tom Steyer become mainstays on the debate stage.
Mr. Booker, despite years of relationships in the finance world of New York and the high-tech corridors of California, had struggled to raise money throughout 2019. All told, he collected about $22.1 million — less than Senator Bernie Sanders of Vermont, Mr. Biden or former Mayor Pete Buttigieg of South Bend, Ind., raised just in the fourth quarter.
Money was so tight that Mr. Booker had scheduled fund-raisers in the final two-week sprint of his campaign in California and New Jersey — far from the crucial battlegrounds of Iowa and New Hampshire.
Mr. Booker had not invested heavily in a digital donor program in advance of his run and he never successfully turned on the spigot of small, grass-roots contributions like some of his rivals. Entering October, he had raised only $4.3 million from donations of less than $200; less than the total haul, for instance, of Mr. Sanders in his first 24 hours as a candidate.
Still, he had an enviable stable of more than 100 bundlers who are now up for grabs, including the billionaire Donald Sussman, one of the Democratic Party’s most generous donors.
In a final push to inch up in Iowa polling and make the January debate stage, Mr. Booker’s campaign ran roughly $300,000 in television ads in Iowa in the past two weeks, a modest sum in a race dominated by the millions spent on the airwaves by Mr. Steyer and former Mayor Michael R. Bloomberg of New York. The ads pushed Mr. Booker’s advertising budget to its limit.
And he struggled to shine as a unique political figure in a crowded and diverse field. His résumé, which had drawn national attention for its breadth throughout his career, was matched at every point. A Rhodes Scholar and former mayor? That also applied to Mr. Buttigieg. The first black person to be elected senator from his state? That also applied to Senator Kamala Harris of California.