The U.S. national debt has now surpassed the size of the U.S. economy, a historic threshold that hasn't been crossed since the conclusion of World War II. Data released by the Bureau of Economic Analysis yesterday showed that the national debt held by the public reached $31.27 trillion as of March 31, while nominal gross domestic product (GDP) was estimated at $31.22 trillion for the 12-month period ending in March. foxbusiness.com