The primary election in California's gubernatorial contest is just over a month away, and the race remains wide open. At a gubernatorial debate this week, a half-dozen Democrats offered divergent views on the state's future — most of whom are within striking distance of each other in the polls — while two Republicans battled for space on the general election ballot. CBS News' California governor's debate Tuesday night featured the largest number of participants to date. The field includes progressive Democratic candidates Tom Steyer and Katie Porter competing against more moderate contenders Xavier Becerra and Matt Mahan, as well as Antonio Villaraigosa and Tony Thurmond.  The top-performing candidate in a recent CBS News poll of the deep-blue state is a Republican — Trump-endorsed Steve Hilton — with fellow GOP contender Chad Bianco trailing a few points behind.…