Is America going broke? Record deficits, colossal debt and no clear plan for digging itself out. If the U.S. sinks, it will take Canada down with it. STEVE MAICH David Walker can see the future, and it scares the hell out of him. That wouldn't be terribly unusual if he were one of the thousands of lobbyists, legislators and activists crawling all over Washington on any given day, pontificating about the urgency of their pet issues. There is a thriving industry here built on pushing policy prescriptions for every ailment, real or imagined. But Walker isn't a lobbyist or an...