FILE - This May 20, 2013, file photo shows Harvard Law Professor David Barron during a forum at the John F. Kennedy Library in Boston. Bolstered by the promised public release of a secret legal memo, Senate Democrats are ready to approve a top federal judgeship for a former official who helped formulate the Obama administration’s justification for the drone killings of suspected American terrorists overseas. The Senate was expected to vote approval on Thursday for David Barron to join the 1st U.S. Circuit Court of Appeals, which is based in Boston. (AP Photo/Michael Dwyer, File)