Though put into question by the holding, and downright contradicted by the concurrence, of Bullock v. Mumford (D.C. Appellate Court, 1974), Greene v. McElroy (1959) has been cited as recently as 1991 in the Supreme Court's own Burns v. U.S. decision for the "right to confront adverse witnesses and evidence in security-clearance revocation proceedings." That said, security-clearance revocation probably is more serious than background-check failure; residents may have fewer rights than citizens in civil due process matters; and we may be surpassing Cold War levels of hysteria in our concern about terrorism.
Clarification: I mean the West Virginia Afsharis, not the California Afshari. California Afshari is pretty definitely sketchy. Also, he's been in the news more lately than WV Afsharis, who seem to have dropped out of press sight since January of this year.