Todd Purdum: "The greatest presidents? Notable business failures almost to a man, if they had any business experience at all. Abraham Lincoln racked up so many unpaid notes in his brief career as a storekeeper in New Salem, Illinois, that he referred to the obligations as his 'national debt.' For 15 years after his haberdashery in Kansas City went under, Harry Truman was still working to pay off his creditors, and was strapped for money until well into his career in the United States Senate. George Washington was a sharp-elbowed, tightfisted planter and entrepreneur (he owned a distillery!), but he spent so much time winning American independence and then inventing the job of president that his financial affairs were a mess by the end of his first term. As for Franklin Delano Roosevelt, the spoiled country squire who led the nation through the Depression and World War II: it could be argued that, until he found his passion in politics, he never really worked a day in his life (even if he put in some desultory time as a Wall Street lawyer)."
"This is not to say that no successful businessmen have ever become president. A few have, among them Warren G. Harding (an Ohio newspaper publisher and editor), Herbert Hoover (a multi-millionaire mining engineer, investor, and consultant), and Jimmy Carter (a Georgia peanut farmer and warehouse owner). But no one would argue that the one-term presidencies of Harding, Hoover, or Carter were anything close to successes."