I think Newsom would be competitive. He'd have 40% locked up of course, along with that any "Blue States". And for Purple States, I think he'd be competitive. He'd tone down some of his previous more liberal commentary and present himself as a "moderately liberal" candidate who merely wants the "rich to pay their fair share", blah blah blah, and "common sense gun control", with as few specifics as possible.
Most liberal positions sound quite good without specifics.