Democratic presidential candidate Joe Biden has announced his running mate.

After promising to select a woman of color for the role, Biden has picked former California Senator and former prosecutor Kamala Harris.

Harris, 55, seen as a rising star within the Democratic party, dropped out of the presidential race in December.

RT reports: Biden announced his pick on Tuesday, with Harris previously considered a front-runner for the post, alongside former National Security Adviser Susan Rice. Earlier in his campaign, Biden had pledged to tap a woman of color for the role, avoiding criticism from progressives centered around his own status as an old, white man.

Harris ran against Biden during primary season, though never found the popularity to challenge the former Vice President the way Sen. Bernie Sanders did. During one particularly heated debate, Harris attacked Biden’s record on racial issues, criticizing the Delaware Democrat for his past relationships with segregationists and his opposition to school busing.

Announcing his choice on Twitter, Biden described Harris as “a fearless fighter for the little guy, and one of the country’s finest public servants.”