Dianne Feinstein has been a U.S. Senator from California for three decades. And before that she was already a powerful figure in San Francisco politics, including serving as mayor. So the announcement that Feinstein is retiring from office at the end of her current Senate term really does mark the end of an era in California politics and governance.  Reporter: Scott Shafer, KQED A new study out of Stanford University finds that enrollment in California public schools fell by about 270,000 during the first three years of the COVID-19 pandemic. Reporter: Amanda Stupi, The California Report Learn more about your ad choices. Visit megaphone.fm/adchoices