State Sen. Marie Alvarado-Gil, midway through her first term in the California legislature, has switched from the Democratic to the Republican Party.

The freshman legislator — who represents rural District 4, the largest senate district in the state in terms of total area and includes part of the Westside in Stanislaus County  — becomes the first Democratic state lawmaker in 80 years to switch party affiliation mid-term, according to the California State Library.

“Since I’ve served in our state’s Capitol, I’ve had a front-row seat to witness the supermajority push California in the wrong direction, having a grave effect on our once Golden state,” Alvarado-Gil said in a press release. “The Democratic Party is unrecognizable to what I once knew and lacks the will to fix the problems plaguing this state. I cannot stand by a party that ignores the will of the people and disregards the core American values that my very community supports and believes in.”

Some see the move as having less to do with political ideology and more with political expediency.

“She won in 2022 because of the way the field worked out for her,” said one Democratic political operative, who spoke on the condition of anonymity. “I just don’t see how there’s any path for her to win again.”

Mike Lynch, a longtime political and policy consultant at the state and federal levels, thinks the move could pay dividends.

“It might work for her politically,” said Lynch. “Even though she will be running as a Republican, she might pick up a lot of Democratic votes from people who’ll say, ‘Hey, she’s done a good job for us, and I’m going to vote for her regardless of what letter is behind her name.’”

Not surprisingly, the move didn’t sit well with the state’s Democratic leadership.

“This is disappointing for voters who elected Sen. Alvarado-Gil as a Democrat,” Senate Pro Tem Mike McGuire (D-North Coast) said in a statement. “They trusted her to represent them, and she’s betrayed that trust. Senate Democrats will continue to work on their behalf and deliver results for rural California. One silver lining is MAGA Republicans are gaining a pro-choice, pro-LGBTQ-plus rights, anti-Trump colleague. We wish her the best of luck.”

Luck, indeed, may have played a role in Alvarado-Gil’s victorious run two years ago, when she battled nine other candidates during the open primary. She hit the electoral lottery as eight Republicans fought amongst themselves and split more than 130,000 votes. That cleared a path for Alvarado-Gil and fellow-Democrat Tim Robertson — they split 90,000 votes — to advance to the general election and deny the ruby-red district a Republican option.

District 4 — made up of all or parts of Stanislaus, Merced, Alpine, Amador, Calaveras, El Dorado, Inyo, Madera, Mariposa, Mono, Nevada, Placer and Tuolumne counties — was just one of six out of 40 senate districts that had more registered Republicans than Democrats.

Overall, District 4 has more than 600,000 registered voters, but only about 220,000 showed up two years ago to vote in the primary, and around 260,000 voted in the general election.

Former Hughson Mayor Jeramy Young, a Republican and the current Police Chief in Livermore, officially filed papers on Thursday to seek the District 4 seat in 2026. 

“My constituents need to know that my values and priorities will not change,” said Alvarado-Gil, who resides in Jackson. “I will continue to fight for economic affordability, public safety, housing, and homelessness. I am excited to work with my Republican colleagues and lead with them in their mission to fix California.”

According to the state library, Southern California state Sen. Jack Tenney was the last Democrat to switch parties mid-term, joining the GOP on Sept. 24, 1944. In the state’s history, 273 legislators have served in more than one political party, with the majority of the switches occurring during the Civil War (1861-1865) and Progressive Era (1900-1930).

The last legislator to switch from the majority to the minority party was Assemblymember Bill Dannemeyer, who served as a Democrat for two terms in the 1960s and then returned as a Republican for one term in the 1970s.