Democratic Rep. Adam Schiff launches bid for Sen. Dianne Feinstein's California seat

Rep. Adam Schiff, who led an impeachment effort against former President Donald Trump, is running for Senate in 2024 for the seat currently held by fellow California Democrat Dianne Feinstein.

"I'm going to the U.S. Senate to fight for working people, not the rich or corporations who don't need yet another voice in Congress," Schiff said in a press release Thursday unveiling his Senate bid.

Schiff's announcement played up his role as a top antagonist of Trump's, portraying the former president's political movement as a major threat to the country.

"I wish I could say the threat of MAGA extremists is over. It is not. Today's Republican Party is gutting the middle class, threatening our democracy," Schiff said in a video accompanying his announcement.

"They aren't going to stop. We have to stop them. That's why I'm running for the U.S. Senate. The struggle isn't over. Not for me, not for them, not for our country," he said.

The 62-year-old Schiff announced his candidacy despite Feinstein, the 89-year-old incumbent, not yet saying whether she will run again.

Schiff is not the only Democratic colleague who is not waiting on her decision. Democratic Rep. Katie Porter announced Jan. 10 that she will campaign for Feinstein's seat. Sen. Elizabeth Warren, D-Mass., has already endorsed Porter.

Schiff has represented his Burbank-area district in Congress since 2001 and served as chairman of the prestigious House Intelligence Committee from 2019 until Republicans won majority control of the chamber following the November midterms.

On Tuesday, newly elected House Speaker Kevin McCarthy, R-Calif., blocked Schiff and another California Democrat, Rep. Eric Swalwell, from serving on the Intelligence committee in the 118th Congress.

Porter's campaign did not immediately respond to CNBC's request for comment on Schiff's announcement. A spokesman for Feinstein's office declined to comment.

Then-House Speaker Nancy Pelosi, D-Calif., tapped Schiff to serve as lead impeachment manager for Trump's first Senate impeachment trial in early 2020. Trump had been impeached in the House on articles of abuse of power and obstruction of Congress, both of which stemmed from the then-president's efforts to have Ukraine announce investigations into his political rivals.

"You can't trust this president to do the right thing, not for one minute. Not for one election. Not for the sake of our country. He will not change, and you know it," Schiff said of Trump in his impassioned closing plea for impeachment.

The Senate acquitted Trump — a move it would repeat a year later, after Trump was impeached a second time on charges of inciting the Jan. 6, 2021, Capitol riot.

Schiff called his work in the trial "the biggest job of my life" in his announcement video Thursday.

In what is likely to become a crowded and expensive race for a Senate seat in the nation's most populous state, Schiff vowed not to accept "a cent" in donations from corporate political action committees. On Jan. 19, Schiff and other Democrats introduced a constitutional amendment to reverse a Supreme Court precedent that allows for unlimited corporate spending in political campaigns.