A Democratic strategist's nightmare vision of an all-Republican governor's race has ballooned into a full-blown campaign to overhaul California's primary system.Steven Maviglio, a longtime Democratic consultant, filed a ballot initiative Friday to scrap California's 15-year-old "top-two" open primary, the system that lets the two highest finishers advance to the general election regardless of party, and revert to a traditional partisan primary, according to The New York Times."Democrats have panicked all year at the possibility that California’s primary rules could shut them out of the governor’s office despite the state having an overwhelmingly Democratic electorate," the Times wrote Sunday.Polling earlier this year showed two Republicans — former Fox News host Steve Hilton and Riverside County Sheriff Chad Bianco — atop the sprawling field for governor while eight Democratic candidates splintered the vote."The fear of having to vote for Steve Hilton or Chad Bianco sent a shiver up my spine," Maviglio told the Times.The proposed initiative, dubbed "Undo the Top Two," is targeting the 2028 ballot and has drawn an unusual cross-partisan coalition that includes Democrats, Republicans, and leaders of the Green and Libertarian parties, both of which have been largely shut out of California general elections since voters approved the top-two system in 2010.Trump endorsed Hilton in April in what some called an act of GOP self-sabotage. Hilton has been at the center of California Republicans' primary chaos for months and recently drew a sharp rebuke from Democratic rival Matt Mahan over his pledge to deliver $3 gas within a year.Former Gov. Arnold Schwarzenegger, who championed the top-two system, blasted the repeal effort. "Of course the politicians want to undo reform that is good for the people and not for the politicians. They will always choose to move the goal posts instead of performing better."