(CNN) Democratic Rep. Katie Porter of California, a first-term lawmaker who has gained wide notice for her forceful grilling of corporate executives in congressional hearings, plans to endorse Sen. Elizabeth Warren for president, two people familiar with the decision told CNN.

Porter, who captured a historically Republican district in 2018, is one of the highest-profile members of the freshman class, and just this week she conducted a scathing interrogation of Mark Zuckerberg, the founder of Facebook, on Capitol Hill.

Her expected endorsement is a coup for Warren, whose rise in the polls has not yet been matched by support from Democratic elected officials. It would also be a blow to Porter's fellow Californian, Sen. Kamala Harris, who has been counting on her home state's primary to help her mount a comeback in the race.

Spokespeople for Warren and Porter declined to comment.

Both Warren and Harris are personally close with Porter, and both senators endorsed her in a competitive primary election last year. Porter is a former student of Warren's at Harvard Law School and, like Warren, is an expert on bankruptcy law. Porter worked closely with Harris when the senator was the attorney general of California, helping oversee a major legal settlement between the state and mortgage lenders.

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