Obama must have picked up some of Alinsky's tactics when he was a "community organizer" in Chicago, but Alinsky died in 1972, when Obama was in grade school. Hillary actually knew Alinsky and wrote her college thesis on him. Obama didn't.
Obama worked directly for a couple of organizations set up by Alinsky- he had ample opportunity to pick up the methods and philosophies, and his campaign is being run along Alinsky principles.
Pick up Revile For Radicals and Rules For Radicals, and Mrs Clinton’s Senior thesis, a must read for political folk.