"I think you've thought long and hard about how to defend the homeland under very difficult circumstances and I want to applaud you for the drone program," he said. " I think it has really helped us in Afghanistan and Pakistan and I believe it is a tactical tool that the President should be using and I think he's using it responsibly."
Graham posited his own hypothetical defending the President's right to order lethal action on U.S. soil if, say, someone hijacked plane and flew it in the direction of a government building. The plane, Graham said, would surely be shot down.
"Wouldn't that be kind of crazy to exempt the homeland, the biggest prize for the terrorists, to say for some reason the military can't defend America here in an appropriate circumstance?" he said.
In both of Holder's exchanges with the lawmakers, the term "imminent threat" was mentioned -- Cruz saying the man in the café was not an imminent threat, Graham saying the hijacked plane was -- but never defined.
Last month the Department of Justice published a document in which it spelled out the circumstances under which the U.S. government could target an American in a foreign country for elimination, and the document contained an unusual use of the term "imminent threat." The document said that in the case of targeting American terrorists, "imminent threat" did not meant that the U.S. necessarily had to have "clear evidence that a specific attack on U.S. persons and interests will take place in the immediate future," but rather a "broader concept of imminence" must take into consideration terrorists who are "continually planning" attacks and the typically limited window during which a lethal operation may be conducted.
It's unclear whether the same broad definition would apply to domestic strikes.