DES MOINES — New Jersey Senator and Democratic candidate Cory Booker says it should be Iowa voters rather than pollsters and pundits who decide whether someone is a “viable” candidate for the White House.

“It is a problem that we now have an overall campaign for the 2020 presidency that has more billionaires in it than black people,” Booker said.

Booker’s comments Thursday in Iowa come after California Senator Kamala Harris exited the race earlier this week. Booker said Harris’ candidacy had energized black women, who are a key constituency in the Democratic Party, and he argued the party’s prospects in 2020 depend on being inclusive.

The more energy and enthusiasm we have from our core, the more we win. I tell you right now, you want to bring a fight, you bring people together,” Booker said. “…You see it in nature. It’s not the queen bee. It’s the swarm.”

Booker delivered a 38-minute speech to a crowd in downtown Des Moines, then spoke with reporters and said there is “anger” that Harris exited the race over campaign finances, but wealthy candidates who can bankroll their own campaigns are still in it.

“This is a very frustrating point in this campaign for me,” Booker said. “…It’s emotional because I had so many people call me and have so many conversations of folks who just feel a sense of unfairness in it all that a woman who is immensely qualified…that she is leaving…and others are still in this race.”

Booker told reporters the party’s rules for qualifying for the televised debates let billionaires “juice up their poll numbers” while candidates like him have to divert resources from their grassroots organizing.

“It’s a shame to be excluded from one when I believe wholeheartedly that my campaign is more significant on the ground on the metrics that matter than other people who are on that stage,” Booker said.

And Booker questioned the statistical significance of the polling threshold a candidate must show, when building a campaign apparatus in Iowa and the other early voting states is more important. Booker is starting a four-day tour through the state with events in 11 Iowa counties.

“Iowa, do not let anybody else decide it for you,” Booker said during his speech today.

Booker was also in Council Bluffs last night, with stops today scheduled in Harlan, Winterset, Grinnell, Waterloo and Manchester.