Elizabeth Warren will endorse Hillary Clinton on “The Rachel Maddow Show” on Thursday, MSBNC said in a statement.

Warren, a potential Clinton pick for vice president, will follow President Obama’s endorsement earlier in the day.

Her endorsement has significance because she has been a star of the progressive wing of the Democratic party, and her nod could help unify party activists. Like Bernie Sanders, she has railed against campaign finance and lobbying, a system that she says is “rigged” in favor of Wall Street and major corporations.

Sanders met with Obama on Thursday but said afterward that he is continuing his campaign into next week, when the District of Columbia holds its primary.

Clinton claimed the nomination on Tuesday, and plans to campaign next week with Obama in Green Bay, Wis.

Warren was one of the few senators not to endorse in the primary, but she did engage in a protracted Twitter war with Donald Trump. Her criticisms led him to call her “Pocahontas.”

Update: In the interview, Warren said that she is “ready to get in their fight and work my heart out for Hillary Clinton to become the next president of the United States and to make sure that Donald Trump never gets any place close to the White House.”

“I think having a fighter in the lead, a female fighter in the lead, is exactly what this country needs,” she said.

She said that Clinton has not talked to her about being a running mate. Asked whether she believed that she could be ready to be president, she said, “Yes, I do.”

She also called Donald Trump “a threat” to the country.