WASHINGTON (AP) — A former Justice Department official who helped craft the Obama administration’s legal rationale for using drones to kill suspected American terrorists abroad won preliminary Senate approval Wednesday to become a federal appeals court judge.

The largely party-line 52-43 vote cleared the way for a final confirmation vote Thursday for David Barron, a Harvard Law School professor. Obama nominated him last September to join the 1st U.S. Circuit Court of Appeals, based in Boston.