After being delayed by a 12-hour long filibuster, the Senate has finally confirmed counterterrorism advisor and US intelligence veteran John Brennan as the head of the CIA in a 63-34 vote. While the result was largely expected, Brennan faced heavy resistance for his role in the Obama administration's drone program, which has used unmanned aerial vehicles in the covert extrajudicial killing of terrorism suspects abroad, including American citizens. Along with the President, Brennan is responsible for overseeing the secret kill list (or "disposition matrix") which the administration uses to determine targets for drone strikes in the Middle East and Asia.

The filibuster, led by Kentucky Senator Rand Paul, didn't focus on Brennan himself, but rather staged a prolonged, mostly symbolic attack on the unaccountable and secretive drone program, which has greatly expanded in the years since the Bush administration. During his confirmation hearing in January, Brennan deftly dodged questions about the Obama administration's justifications for the targeted killing of American citizens using drones, which cited the 2011 killing of American-born Muslim cleric Anwar al-Awlaki and his 16-year-old son, Abdulrahman. The questions came just after the leak of a confidential Justice Department memo which contained a legal argument for killing Americans that broadly redefined an "imminent" attack to include any threat of harm to the US which may or may not occur in the near future.

Much of the ire during Paul's filibuster reflected incendiary statements made Tuesday by Attorney General Eric Holder, who said that the Obama administration wouldn't rule out a drone attack against an American citizen on US soil under "extraordinary circumstances." Holder later added that he misunderstood the question, clarifying that the government can not kill an American who is "not engaged in combat" on US soil — though the government's own targeting of noncombatants abroad makes those definitions of engagement still unclear (the administration considers all men of military age in designated areas to be "militants").

Paul also acknowledged a wide range of reports which found that the vast majority of drone strikes are actually "signature strikes," attacks which kill anonymous individuals based purely on observed behavior in the field, and stand apart from the targeted strikes which the administration has partially acknowledged. There are still no official numbers for the collateral damage caused by drone strikes in Pakistan and elsewhere, but even the most conservative estimates plot the number of civilian casualties since 2004 somewhere in the hundreds. Brennan himself has resisted answering any questions about civilian deaths, but more recently has said that the data on civilians should be public.

"I would suggest the idea that we should simply trust the Attorney General, trust the director of the CIA, Trust the President to exercise an astonishing power to take of life of any U.S. citizen — that trust, in my judgment, is fundamentally inconsistent with the bill of rights," said Senator Ted Cruz (R-TX) as the filibuster entered its fourth hour. Paul attracted widespread support as the hours passed by. Florida Senator Marco Rubio, fresh off his lucrative water bottle incident, also rose to offer his support by quoting "a modern day poet, Wiz Khalifa." And Republican leader Mitch McConnell, also from Kentucky, commended Paul for his "extraordinary effort."

Not all of Paul's fellow Republicans supported his objections, however. Senators John McCain (R-AZ) and Lindsay Graham (R-SC) rose in opposition, with McCain calling the filibuster "a disservice to Americans." While not nearly approaching Strom Thurmond's legendary 24-hour record, the lengthy proceedings continued for nearly 13 hours, with Paul eventually yielding the floor after saying "I’ve discovered there are some limits to filibustering, and I’m going to have to take care of one of them in a few minutes."