OAKLAND -- Clipboards in hand, high school seniors Estephania Franco and Jocelyn Sanchez approached a group of UC Berkeley students sitting on a curb in Sproul Plaza. "Hey guys, you want free tuition?" one of them asked. "Free? Tuition?" sophomore Josh Netter asked, as if waiting for the punchline. "I just feel like it's too good to be possible." It wouldn't be -- if, by June, supporters of the "College for California" ballot petition managed to gather the signatures of 807,615 people registered to vote in California. And, of course, if voters approved it. The proposed constitutional amendment, researched and...