A Republican senator seeking to block President Barack Obama's pick to lead the CIA over concerns about drone strikes on US soil completed a nearly 13-hour speaking filibuster early Thursday.
In a remarkable display highlighting the partisan rift in Washington, Rand Paul led the filibuster of John Brennan's appointment after the White House refused to unequivocally rule out drone strikes on US soil.
Senate Majority Leader Harry Reid, a Democrat, tried to bring the blocking tactic to a close, but Paul, a favorite of the Republican Party's conservative Tea Party faction, refused to stop.
His oratory held up any other Senate action as he railed against US policy on targeted killings from 11:47 am (1647 GMT) Wednesday until 12:39 am (0539 GMT) Thursday -- a total of 12 hours and 52 minutes.
During the marathon delaying tactic, Paul said he would be happy to yield the floor "if the president or the attorney general will clarify that they are not going to kill non-combatants in America."
The issue has gained fresh currency on Capitol Hill, with senators from both parties pressing Attorney General Eric Holder on whether the administration believes drone attacks on American soil could be justified.
Paul demanded answers from President Barack Obama on the secret unmanned aerial drone program, which has emerged as the most contentious element of Brennan's nomination to head the Central Intelligence Agency.
"I rise today to begin to filibuster John Brennan's nomination for the CIA," he said shortly before noon.
"I will speak until I can no longer speak. I will speak as long as it takes, until the alarm is sounded from coast to coast that our Constitution is important, that your rights to trial by jury are precious, that no American should be killed by a drone, on American soil, without first being charged with a crime, without first being found guilty by a court."
He finally yielded the floor after midnight, to a round of applause.
"I've discovered that there are some limits to filibustering and I'm going to have to take care of one of those in a few minutes here," he joked.
Paul later said he hadn't planned the move ahead of time.
"My legs hurt, my feet hurt, everything hurts right now," he told reporters afterwards. "I didn't wear my most comfortable shoes or anything. I would have worn different shoes."
Brennan's nomination easily cleared the Senate Intelligence Committee Tuesday, despite fury from leading Republican lawmakers at what they said was a lack of disclosure over last year's attack on the US mission in Benghazi, Libya, which killed four Americans, including US ambassador Chris Stevens.
The Senate plans to vote on Brennan by Saturday at the latest.
At close to the 12-hour mark, Senate Minority Leader Mitch McConnell joined the filibuster, saying: "I intend to oppose the nomination and congratulate my colleague from Kentucky for this extraordinary effort."
Paul had earlier enlisted Republicans Mike Lee, Ted Cruz and Saxby Chambliss. Rising Republican star Marco Rubio also joined, as did Democrat Ron Wyden, who has long questioned White House power on national security issues.
"You are raising some of the most important questions... we could be asking," Wyden said. "This is just the beginning of this debate."
Tea Party-backed Cruz, noting that Paul might be unaware of the goings on in the outside world, told him Twitter was "blowing up" over his filibuster and proceeded to read out more than a dozen tweets in support of his colleague.
Paul had threatened to filibuster Brennan's nomination as early February 13, when he demanded answers from the administration about the president's power to authorize lethal force.
Holder responded Tuesday, stressing that while Obama had "no intention" of ordering drone strikes on US soil, the scenario could be possible if there were an "extraordinary circumstance" such as a 9/11-style attack.
Paul reacted with revulsion, saying he had expected an "unequivocal 'no.'"
And he insisted his critique was not partisan, saying: "Were this a Republican president, I'd be here saying exactly the same thing."
Paul acknowledged that US drone strikes have proven effective in places like Pakistan and Yemen, including a strike on US-born radical preacher Anwar al-Awlaki, whom Paul branded a traitor.
But "if you're going to kill non-combatants, people eating dinner, in America, there have to be some rules," he added.
Paul's effort recalled the classic "talking filibusters" of old, famously portrayed in the fictional 1939 classic, "Mr. Smith Goes to Washington," starring Jimmy Stewart.
But Paul acknowledged Brennan was a virtual lock for the CIA, calling the filibuster "a blip" in the process.