Sen. Dianne Feinstein announced last week that she will not run for reelection, sounding the official starting gun for the 2024 campaign to succeed her in the Senate. As the race gets going, it probably makes sense to ask a fundamental question: What should Californians be looking for in their next U.S. Senator?

Feinstein’s storied career offers some clues.

Look, I’m biased. I had a front-row seat to her tenure in office, and I saw her at her peak. She was a force of nature. She viewed her job as solving problems for the people of California and the nation.

Her Senate colleagues lived in fear that she would buttonhole them on the Senate floor to get them to sign on to one of her priority bills. When she was trying to round up votes, she was relentless. How else do you think she was able to get the 1994 Federal Assault Weapons Ban passed over the virulent objections of the NRA? How else do you think she was able to publish the Senate Intelligence Committee’s torture report over the concerns of the CIA?

Now some may say — and boy, do they — that her time has passed. That at 89 years old, she doesn’t understand the super-polarized politics fueled by cable news and social media bubbles. That may be true.

But Feinstein has a much deeper understanding of California than those pundits and advocates ever will. That’s why she was the state’s most popular politician — with approval ratings above 50% — until just a few years ago.

From my vantage point, it comes down to three things.

Feinstein is many things, but first and foremost she is a passionate advocate for the principles she holds dear. She’s led the fight for reproductive freedoms before, during and after the Roe era. More than anyone else, she has stood up against gun violence and for common-sense gun regulations. She passed legislation to increase fuel economy standards for automobiles and light trucks. She sponsored the reauthorization of the Violence Against Women Act and led the effort to successfully repeal the Defense of Marriage Act (which prevented the federal government from recognizing same-sex marriages) after being one of only 14 senators to vote against it in the first place.

Second, when it comes to fighting for the people of California, you must build alliances — and, yes, that includes with Republicans. The Senate is a small place. You can’t pass anything of consequence without 60 votes. So on the Lake Tahoe Restoration Reauthorization Act, she worked with Republican Sen. Dean Heller of Nevada to get it passed. On criminalizing cross-border tunnels from Mexico into the United States, she worked with Sen. Jon Kyl of Arizona. And on stopping the accessibility of precursor drugs needed to cook meth, she worked with Sen. Jim Talent of Missouri.

Finally, she never lost sight of why the people of California sent her to Washington. It certainly wasn’t to score points on Twitter. California faces enormous challenges. It is the size of 20 other states and the District of Columbia combined but only has two senators. The state needs an advocate who will work to stop global warming and fight for dollars to address the state’s water crisis and catastrophic fires; to make sure that there’s someone working day and night to make sure our nation is safe and our economy is strong.

Feinstein did all of that and more. As the curtain on her career draws to a close, we should remember why she was elected to the Senate six times. I’m hopeful that California will elect someone who brings the passion, the principles, the energy and the indefatigable work ethic that Feinstein brought (and still brings) to the office.

Scott Gerber is the former communications director for U.S. Sen. Dianne Feinstein and founder and partner of Vrge Strategies. He wrote this commentary for CalMatters.