House Speaker Nancy Pelosi on Thursday said Sen. Bernard Sanders of Vermont shouldn’t yet step aside in the 2020 presidential race, saying activists want to see the process play out.

“In case you were going to ask, no, I don’t think Bernie Sanders should get out of the race,” the California Democrat told reporters. “I’m a grassroots person. … I know the enthusiasm of supporters for candidates, and they want to see it play out.”

“I congratulate both of the candidates as they go into the debate on Sunday, wish them both well,” she said. “I’m very pleased we’re getting a chance now in a narrower field to be able to come close to having a standard-bearer for the party.”

Earlier this week, House Majority Whip James Clyburn told NPR it might be time for the Democratic National Committee to step in and cancel future debates with former Vice President Joseph R. Biden looking like the prohibitive favorite to win the party’s presidential nomination.

Mr. Clyburn endorsed Mr. Biden ahead of the South Carolina primary, which helped reawaken the former vice president’s slumbering campaign.

Since South Carolina, Mr. Biden has racked up a series of wins to the point where it would take a significant collapse on his part for Mr. Sanders to overtake him in the race for delegates in the near future.

Mr. Sanders on Wednesday said he was pressing on with his campaign and that he looked forward to Sunday’s debate against Mr. Biden. He signaled he could use the time to hold his rival’s feet to the fire on a host of issues important to progressives.