The announcement comes after Republicans blocked the California Congressman from serving on the prestigious House Intelligence Committee, a powerful post Schiff wielded like a bully pulpit to scrutinize and criticize the former president.

UPSOUND SCHIFF:

"This White House operates under a very different set of rules."

From early days of the Trump administration Schiff emerged as a chief rival to the Republican leader, championing a special counsel's probe into the Trump campaign's ties to Russia...

UPSOUND SCHIFF:

"... so our investigation is really getting under way."

...and later, when he became the chairman of the House Intelligence Committee, he took a lead role in Trump's first impeachment trial over the president's alleged efforts to extort a foreign government's help in tarnishing the reputation of Democratic presidential candidate Joe Biden.

UPSOUND SCHIFF:

"Donald J. Trump sacrificed our national security in an effort to cheat in the next election, and for that, and his continued efforts to seek foreign interference in our elections, he must be impeached."

Schiff's efforts earned him the unvarnished vitriol of the 45th president and his Republican allies.

UPSOUND TRUMP:

"I learned nothing from Adam Schiff. I think he's a maniac. I think Adam Schiff is a deranged human being. I mean, he grew up with a complex for lots of reasons that are obvious. I think he's a very sick man and he lies."

And Kevin McCarthy, the new Republican Speaker of the House, has banned Schiff from serving again on the House Intel panel.

The 62-year-old Schiff has now set his sights higher.

Schiff joins other California Democrats, including U.S. Representative Katie Porter, aiming for the seat currently held by 89-year-old Democratic Senator Dianne Feinstein.

She is the oldest member of Congress, and has a record as a trailblazer: Feinstein was the first woman to serve as mayor of San Francisco, the first woman on the Senate Judiciary Committee, and the longest-serving woman in the Senate.

Feinstein has not said whether she will seek re-election in 2024. If she does, and wins, she would be 97 at the end of her six-year-term.

In a statement announcing his Senate bid, Schiff said "I look forward to campaigning hard in this race."