After suspending his campaign for president, Sen. Bernie Sanders, I-Vt., said he will work hard to make sure that Joe Biden becomes president, but added, “He’s going to have to listen to and respond to the needs of a whole lot of people who have not been overly enthusiastic about his campaign up to now.”

Sanders said the former vice president will have to do a better job reaching out to young and low-income voters to defeat President Donald Trump.

Despite suspending his campaign on Wednesday, Sanders’ name will remain on the ballot in the coming primaries and he will likely continue to amass delegates. “We would like to get as many delegates as we can so that we have a stronger position at the Democratic convention to help us shape the new platform of the Democratic Party and other issues that the DNC deals with,” Sanders said in an interview with PBS NewsHour anchor and managing editor Judy Woodruff on Friday.

Looking back at the successes of his campaign, Sanders said he believes he has won the ideological battle. “Ideas that I fought for four or five years ago, which everybody considered to be radical and extreme, are now part of the mainstream discussion,” Sanders said. He also said his ideas represent the future of the country because they are popular with young people. “We did very poorly, and I don’t know why, to tell you the truth, with older people,” Sanders said. “But we have done phenomenally well with younger people.”

Since announcing he was ending his race, Sanders said he has been on the phone with progressives across the country to talk about where the movement he built will go from here. “We are a strong movement and history will determine what happens in the future,” he said.

More highlights from the interview: