Can the president legally order a drone strike to kill an American on U.S. soil? Attorney General Eric Holder wrote this week in a letter to Sen. Rand Paul, R-Ky., that he could envision “an extraordinary circumstance in which it would be necessary and appropriate” to use such lethal force.

Those words touched off a heated debate in the Senate on Wednesday over when and where the president can order the killing of U.S. citizens designated as enemy combatants.

President Obama and his aides have said that targeted killings of Americans must be governed by some due process. But they have resisted public disclosure of their rules. Until this week, the administration had refused to allow even members of the Senate Intelligence Committee to read most of the legal opinions that justified the one known drone killing of an American, the attack on Anwar al-Awlaki in 2011 in Yemen.

The debate burst into public view on Capitol Hill. On the Senate floor, Paul filibustered the nomination of John Brennan to be the new director of the CIA, imploring colleagues to join him and criticizing Obama for refusing to categorically rule out the use of lethal force against terror suspects in this country.

Brennan has been a chief architect and defender of the administration’s drone war.

“Are we so complacent with our rights that we would allow a president to say he might kill Americans?” Paul asked. “No one person, no one politician should be allowed to judge the guilt of an individual and to execute an individual. It goes against everything we fundamentally believe in our country.”

Paul showed no sign of giving up, holding the floor for more than eight hours and continuing to talk into the night. He demanded a public promise from the White House to never target drones against Americans in the United States. Paul insisted he was not objecting to the use of lethal force to repel an attack but said the administration was claiming a far broader power.

“Do we want martial law in this country?” Paul asked, mocking the claim that the entire world can be considered a battlefield in the war against al-Qaida and other terrorist groups. “The hell this is a battlefield! This is our country.”

“If there was an ounce of courage in this body, I would be joined by others in telling the president that no president has the authority to kill Americans without trial,” Paul declared to a near-empty chamber.

As the afternoon wore on, his words appeared to have had an impact, as several Republican colleagues and Democrat Ron Wyden of Oregon joined the filibuster, delaying a final vote on Brennan’s nomination at least until Thursday.

Simultaneously, Holder was testifying to the Senate Judiciary Committee, where senators tried to pin him down about the limits of the power the government was claiming.

In his letter, Holder had said he hoped “no president will ever have to confront” the need to order the killing of an American on U.S. soil.

But, he added, “it is possible, I suppose, to imagine an extraordinary circumstance in which it would be necessary and appropriate under the Constitution and applicable laws for the president to authorize the military to use lethal force within the territory of the United States.”

He mentioned the attacks on the World Trade Center and the Pentagon on Sept. 11, 2001, as a possible example.

Holder also said he expected Obama to speak more publicly about the issue in the near future. “I think there is a greater need for transparency, a greater need for appropriately sharing information, and we are struggling with how to do that, but it is something that the president feels strongly about,” he said.

Sen. Lindsey Graham, R-S.C., applauded the administration’s drone policy. “In every war we’ve had, unfortunately, American citizens have sided with the enemy. They’ve been few in number, but that does happen,” he said.

A battery of Patriot missiles now guards the U.S. Capitol against attack, Graham noted.

“Let’s go back in time,” he said. “What would we all give to have those Patriot missile batteries available” on Sept. 11.

Using them to blow up one of the airliners aimed at the World Trade Center or the Pentagon “would have meant that we would have lost a planeload of American citizens, but we’d save thousands more. That’s the world in which we live in,” he said.

Holder repeatedly told the committee his letter had merely dealt with the unlikely possibility of an extreme event.

He stressed that there is no plan to broaden the administration’s drone program to aim at targets inside U.S. borders.

Finding and isolating terrorists abroad is much harder than in the U.S., often making capturing a suspect impractical, he said. In the U.S. many law enforcement tools exist that allow officials to capture suspects without killing them.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.