Sen. Cory Booker (D-N.J.) on Monday suspended his campaign for the Democratic presidential nomination, saying he no longer has a path to victory in the race to challenge President Donald Trump .

Our campaign has reached the point where we need more money to scale up and continue building a campaign that can win money we dont have, and money that is harder to raise because I wont be on the next debate stage and because the urgent business of impeachment will rightly be keeping me in Washington, Booker wrote in an email to supporters.

Bookers departure from the race, which comes not long after former Housing and Urban Development Secretary Julian Castro dropped out, means only a handful of candidates of color remain in the race and none are considered serious contenders for the nomination. The next Democratic primary debate, scheduled for Tuesday, will feature only white candidates.

Booker, a former mayor of Newark, New Jersey, officially entered the race on Feb. 1, 2019, the first day of Black History Month. Throughout his campaign, he routinely spoke more pointedly about the plight of Black Americans than any other candidate. In a video kicking off his run, Booker introduced himself by discussing his parents experience with housing discrimination as they sought a middle-class life for him and his brother in New Jersey. Booker had a similar tact with issues like gun violence and education, speaking broadly about the impact these issues have on all Americans while also discussing the ways they acutely affected Black people.

The Booker campaign also largely shaped the primarys debate around gun violence. The senator was the first candidate to call for a federal gun licensing program, something more than a dozen other candidates eventually said they supported.

But in polls, Bookers support hovered stubbornly in the low single digits, and the candidate struggled to broaden his support among Black voters. Although Booker frequently drew praise from activists and polling indicated many Democratic voters had a favorable opinion of him, he struggled to convince voters he should be their first choice.