WASHINGTON – In sheer size, the economic measures announced by President Barack Obama to address "a crisis unlike we've ever known" are remarkable, rivaling and in many cases dwarfing the New Deal programs that Franklin D. Roosevelt famously created to battle the Great Depression. Winning approval was a political tour-de-force for the new administration. Yet gloom and uncertainty persist about the plan's ability to deliver a cure for the economy's severe ailments. Stocks plunged to six-year lows after the burst of bill signings, bailout announcements and presidential pledges.