For his entire presidency, George W. Bush has tried to avoid the fate of his father, brought low by a feeble economy. Now, as the financial crisis radiates far beyond Wall Street, Mr. Bush faces an even grimmer prospect: being blamed, at least in part, for an economic breakdown. “There will be ample opportunity to debate the origins of this problem,” Mr. Bush said in the Rose Garden on Friday. “Now is the time to solve it.” But in Washington, on Wall Street and on the presidential campaign trail, the debate has already begun. Senator Barack Obama, the Democratic presidential...