A 'jungle' primary: Behind the chaos of the Super Tuesday 2024 California Senate race

California's registered Democratic voters outrank Republicans by a ratio of nearly 2-to-1, yet the latest polling suggests a Republican could spring past two popular Democratic lawmakers in the primary race for Senate on March 5.

How is that possible? Look to the Golden State's unique nonpartisan primary system for the answer. It's one of just a few states in the nation to hold what is commonly called a "jungle" primary, where registered voters regardless of their political party affiliation can cast their vote for whichever candidate they prefer. Once votes are tabulated, those with the two highest numbers of votes — also regardless of their party affiliation — advance to the November general election ticket.

The top four candidates in the primary are Democratic Reps. Adam Schiff, Barbara Lee and Katie Porter, and Republican former baseball star Steve Garvey.

For a while last year, Reps. Schiff and Porter were thought to be headed to snatch the top two spots, but latest polling shows Porter and Garvey dueling for second place behind Schiff. As a result, Super Tuesday's primary will produce one of two possible scenarios, each of them consequential: either a Democrat-on-Democrat race between Porter and Schiff, or a Republican-Democrat faceoff between Garvey and Schiff.

More: Latest Calif. Senate race poll: Garvey's support surges, increasing odds of faceoff with Schiff

The first scenario would crank up Democratic spending, turning what is already the state's most expensive Senate contest in history, per AdImpact data, into an even larger morass that some experts worry could siphon funds from other races. The second, in which California sees a Republican and Democrat on the November ticket, would do the opposite. In such an overwhelmingly blue state, where a Republican has not held statewide office in decades, Garvey stands little chance of defeating longtime representative and former Trump impeachment prosecutor Adam Schiff.

California switched to a top-two primary system in 2011, which does not apply to elections for U.S. President, county central committees or local office races. In a statement released at the time, then-California Secretary of State Debra Bowen praised the new process, saying it "simplifies the process and offers more choices."

However, it has been heavily criticized by both Democrats and Republicans since taking effect, saying it could lead to one party shut out of the general election, and alleging it encourages strategies that some disagree with. Specifically, this includes Schiff's tactic of highlighting his Republican competitor in ads rather than Democrat Porter, who would be a tougher opponent provided the state's Democratic majority.

Analysts and pollsters have recently pointed to Schiff's ads, 60% of which AdImpact say mention Garvey, as a reason behind the Republican's surging numbers. Porter has been heavily critical of the ads, calling them "brazenly cynical" in a February post on X, formerly Twitter.

While voters navigate this nonpartisan "jungle" primary format, this year they must also reckon with ballots that list the open seat twice.

The Senate race is to fill late-Dianne Feinstein's seat, which she held for 30 years until her death in September at the age of 90. As a result, voters will be faced with two Senate race options on their March primary ballots — one for the remainder of Feinstein's term ending Jan. 3, 2025, and the other for a full six-year term ending 2031. The same goes for November ballots.

The primary race for the full-term Senate seat is infinitely more crowded, with 27 names, while the choice for the partial term has just seven. The top four candidates Garvey, Lee, Porter and Schiff will be on both primary ballot questions.

More: 10 California House races to watch in 2024

Kathryn Palmer is the California 2024 Elections Fellow for USA TODAY. Reach her at [email protected] and follow her on X @KathrynPlmr.

This article originally appeared on Palm Springs Desert Sun: Why Super Tuesday's California Senate primary is dubbed a 'jungle'