In Greene v. McElroy, the U.S. Supreme Court looks at whether the due process clause was violated when the federal government took away an aeronautical engineer’s security clearance without a hearing. The clearance was taken away because of suspicions that the engineer’s ex-wife had been associated with members of the Communist Party. Although employed by a private company, the engineer worked on projects for the federal government and had access to classified information. The zvourt says that because loss of his clearance deprives the engineer of his right to practice his chosen profession, the due process clause requires a full hearing where the engineer could confront and cross-examine witnesses against him.