Goldman Sachs Chief Executive Lloyd Blankfein has hired Reid Weingarten, a high-profile Washington defense attorney whose past clients include a former Enron accounting officer, according to a government source familiar with the matter. Blankfein, 56, is in his sixth year at the helm of the largest U.S. investment bank, which has spent two years dodging accusations of conflicts of interest and fraud. The move to retain Weingarten comes as investigations of Goldman and its role in the 2007-2009 financial crisis continue. The U.S. Securities and Exchange Commission scored a $550 million settlement against the bank in a fraud lawsuit in...