President Barack Obama will try to recapture the magic of his 2008 youth vote next week, pulling out some of the organizational tricks of his presidential campaign at a massive rally at the University of Wisconsin in Madison. His political arm, Organizing for America, will be collecting email addresses and pressing students to sign pledge cards swearing they will vote in November. Those cards will be sent back to them closer to Election Day. Volunteers will also push students to sign up for text-messaging alerts Tricks like that were staples of the Obama presidential campaign, which built up a vast...