WASHINGTON -- Senators on Wednesday criticized Attorney General Eric Holder for the secrecy surrounding the Justice Department legal memorandums justifying drone strikes aimed at American citizens, while pushing him to say more about when the Obama administration believes it can use military force on U.S. soil.As Holder came before the Senate Judiciary Committee for an oversight hearing, the chairman of the panel, Sen. Patrick Leahy, D-Vt., said he was considering issuing a subpoena to the executive branch to compel it to turn over the Justice Department documents.The ranking Republican on the panel, Sen. Charles Grassley of Iowa, also expressed frustration over the administration's refusal to allow access to the documents.Holder said that he was "sympathetic" to the committee's desire to see the documents, but that the decision to share them was not his alone. He said the administration was struggling with how to provide more information about targeted killings and drone strikes.One focus of the hearing was the extent to which the administration believed it could authorize the military to use lethal force, like drone strikes, against American citizens on domestic soil. Earlier this week, Holder sent a letter to Sen. Rand Paul, R-Ky., saying that the question was "entirely hypothetical" and "unlikely to occur," but that it was possible to imagine circumstances in which it would be appropriate, such as during an attack like the one at Pearl Harbor or the ones on Sept. 11, 2001.Sen. Ted Cruz, R-Texas, suggested a hypothetical situation in which a terrorism suspect was not presenting an imminent threat -- like "sitting in a cafe," rather than pointing a weapon -- and asked whether it would be unconstitutional to simply kill that person.Holder repeatedly said that would not be an appropriate time to use lethal force rather than arresting the suspect, but Cruz said he was asking a "simple question" about whether it would be legal, not its propriety. Finally, Holder said "translate my 'appropriate' to 'no.' I'm saying 'no.'"Cruz replied that he was glad that "after much gymnastics," he had obtained the answer, adding that he wished Holder had given the same statement in the letter to Paul.