Sen. Elizabeth Warren sent a blistering letter to Federal Reserve chair nominee Kevin Warsh on Thursday, predicting he would serve as a "rubber stamp for President Trump's Wall Street First Agenda," and accusing him of having learned "nothing from your failures" during a prior stint at the central bank. Warren, D-Mass, in the letter reported first by CNBC, told Warsh that his record as a member of the Fed's Board of Governors from 2006 until 2011 — which included the 2008-09 financial crisis