The chair of the Congressional Black Caucus, Rep. Karen Bass, D-Calif., is endorsing former Vice President Joe Biden for president, throwing her support behind the frontrunner in the Democratic primary race.

Bass told the PBS NewsHour in an interview Thursday that she believes Biden has the best chance of beating President Donald Trump in the general election. She argued that Senator Bernie Sanders, I-Vt., failed to build strong relationships with black lawmakers and black voters across the country. She also noted that Biden reached out to ask for her endorsement soon after he decided to run for president and that Sanders, who is now trailing Biden in the delegates needed to win the nomination, did not ask for her endorsement.

“I am absolutely excited about endorsing the vice president now,” Bass said of Biden. “We need somebody who is steady, who is clearheaded, and who is focused on the nation, and not himself.”

Bass made the decision after speaking with members of the Congressional Black Caucus, she said. At least 39 lawmakers in the group have endorsed Biden while only one member — Rep. Ilhan Omar, D-Minn. — has endorsed Sanders. Bass said Biden winning the support of black voters by big margins across the country in the primary contests illustrates that he took the time to build relationships with those communities.

“The way he was involved with communities during his vice presidency gives him a level of closeness and contact with our community, but other communities as well,” Bass said of Biden. “I think it shows his historic connection with African Americans. I think that Senator Sanders does not have a historic connection like that.”

She said if Sanders had closer ties to black voters, she doesn’t believe the margins would be so wide in states like Mississippi, where 84 percent of black voters supported Biden while 13 percent supported Sanders, according to exit surveys from their March 10 primary.

“I know one thing, if I were going to run for president, I would work years in advance on building ties and building relationships — not just with African Americans — with all communities,” Bass said, adding that she believes Sanders failed to do that.

Bass noted that while the Vermont senator reached out to her once, around a year ago, she and Biden have spoken “a number of times” throughout the campaign.

“Senator Sanders called one time,” Bass said. “We didn’t have a conversation. He was inviting me to meet with him. But it was at the last minute, I wasn’t able to do it, and I never heard back.”

Rep. G. K. Butterfield, D-N.C., a former chair of the Congressional Black Caucus, endorsed Biden months ago and said Biden has a “deep relationship with the African American community.”

“Senator Sanders is a very idealistic person,” Butterfield said. “He grew up in New York and he spent most of his life in the New England states, and I’m not sure what he has the ability to connect with the soul of African Americans who reside in the south.”

However, some younger activists who are part of the Black Lives Matter movement have said that their political views have been represented in Sanders’ campaign thanks to his anti-establishment platform. For some of these voters, Biden only represents moderate change rather than the revolution they want to see happen.

The endorsement by Bass comes after the World Health Organization deemed the coronavirus a pandemic. Bass said the unfolding crisis illustrates why Biden would be a better president than Trump.

“More than anything to me, his knowledge of international leaders, and his overall presence and standing is just exactly what we need right now,” she said of Biden. “I certainly have disagreed with various positions. But what I’ve never questioned was his commitment to the country.”

Bass argued that Trump’s response to the novel coronavirus crisis illustrates that the country needs new leadership.

“I think that the way Trump is handling the coronavirus is really indicative of how he has led over the last three and a half years–by lying on a daily basis,” she said. “We are facing a pandemic, and one of the reasons why there’s so much chaos now is because we know we cannot believe anything that comes out of his mouth.”

If Biden wins the nomination, Bass said she hopes Sanders will encourage his supporters to rally behind Biden. Though, Bass also said ultimately, she would support Sanders if he becomes the nominee, though his path to the nomination has narrowed significantly.

“The most important thing to me in the world is for Donald Trump to not have four more years,” she said.

Meanwhile, Butterfield said he hopes Sanders ends his campaign soon.

“It’s like different stages of death. You have to work through different stages of defeat,” he said “But I hope he’s winding down his campaign and talking to his supporters so that we can have unity in November.”