Paul Beach may not feel the weight of it, but he's a linchpin in making the federal health care overhaul work. He's 28, fully employed and uninsured. "I want insurance," he said. "But it's a tossup between eating food or buying health insurance. I'd need a second job just to pay the insurance." As Minnesota and other states get ready to launch new insurance exchanges on Oct. 1, one of the big challenges is persuading people like Beach to buy coverage. Minnesota's MNsure exchange is firing up an all-out marketing blitz, with young adults one of the key audiences.