(By Jeff Chidester, director of Policy and Tony Lucadamo, lead policy analyst at the University of Virginia’s Miller Center) The U.S. is slowly building momentum for two historic trade pacts: The Trans-Pacific Partnership (TPP) and the Transatlantic Trade and Investment Partnership (TTIP).  But without trade promotion authority (TPA) – which grants the president the right to negotiate a non-amendable deal with expedited floor debate – these deals will never pass.  So say America’s lead trade negotiators, past and present.