Former baseball player Garvey faces prominent Democrats for Feinstein's California Senate seat(Part-1) .

Los Angeles — A crowded primary contest to fill the U.S. Senate seat once held by late Democratic Sen. Dianne Feinstein is showing again that money matters in notoriously expensive California and testing whether the state's long-battling Republicans can unite behind a single candidate for an outside shot. County ballots must be mailed by Monday to begin voting.

Adam Schiff, a Democrat, has dominated fundraising and polling since becoming the chief prosecutor in then-President Donald Trump's first impeachment trial. However, many people are unsure before the March 5 election.

Without regard to party, California primary ballots include Democrats and Republicans, and the two candidates with the most votes advance to the general election. Schiff, who has spent a lot of money on TV, cable, and streaming commercials, looks to be the best candidate for one of the two November spots.

Reps. Barbara Lee and Katie Porter, two more prominent Democratic House members, and former Los Angeles Dodgers player Steve Garvey, a Republican and former National League MVP who is running for government 37 years after leaving from baseball, are also pursuing him.

More than two dozen names will appear on the Senate ballot for the six-year term starting next year, many of them political unknowns. On November, Democrats are poised to retain the seat in a state where Republicans haven't won a Senate race since 1988.

Porter's campaign has been attacking Garvey, saying that his celebrity might “be the reason we lose Katie's voice in Congress for good” as Schiff appears likely to grab one of the November places. Schiff's statewide commercials brand Garvey “too conservative for California,” which may be meant to boost his reputation with conservatives and hurt Porter's chances because Garvey is a longshot in the fall.

According to Porter, Schiff is trying “to game the system to get an opponent they have the best chance of defeating” in November. Feinstein died in September after a lengthy career breaking gender barriers and advocating for abortion and gun control. Laphonza Butler, a veteran Democratic activist, was selected to replace Feinstein's term by Democratic Gov. Gavin Newsom and did not run for office.

The state's once-booming population is declining, and polls suggests many Californians are dissatisfied with the state's direction, inflation, and an unaddressed homeless epidemic in Los Angeles and other large cities. Presidential contest might sway results and lower attendance on both sides.