The US Senate gave Ben Bernanke a second four-year term as the head of the Federal Reserve on Thursday after critics excoriated the central banks conduct in the years leading up to the financial crisis. The 70-to-30 vote was the weakest endorsement ever extended to a chairman in the Feds 96-year history. The confirmation was a victory for president Barack Obama,who had called Bernanke an architect of the recovery,but also signaled the extent to which the Fed has become the object of outrage.