Sen. Rand Paul (R-KY) surprised the Senate on Wednesday with the longest filibuster in over twenty years, using almost 13 hours of time on the Senate floor to demand more information and answers from the Obama Administration on whether drones could be used against Americans - on U.S. soil - who are suspected of terrorist activities.

Paul was joined by many fellow Republican Senators, and watched by a number of House GOP lawmakers who walked across the Capitol to witness his filibuster; he made clear he knew his delaying tactics on the CIA nomination of John Brennan would not work - but Paul said he deserved better answers from the President and the Obama Administration on the use of drones.

"It's an easy question," Paul said of what he asked the White House.

"When I asked the President, can you kill an American on American soil, it should have been an easy answer," Paul said as he opened what turned into the longest filibuster since Sen. Al d'Amato (R-NY) kept the floor for 15 hours and 14 minutes in 1992.

Other GOP Senators joined Paul in rapping the White House for what a number described as "evasive" answers about a hypothetical drone attack in the U.S.

"You've asked a straightforward question, and yet you haven't received a straightforward answer," said Sen. Marco Rubio (R-FL) to Paul.

"Getting the right information out of this administration has been worse than having a root canal and more difficult than having a root canal," said Sen. Saxby Chambliss (R-GA), who is the top Republican on the Senate Intelligence Committee.

Here is video of some of Paul's remarks on the Senate floor:

For those unfamiliar with the Senate rules, Paul had to remain on his feet the entire time, and was not allowed any bathroom breaks, though he did seem to sneak a candy bar at one point during the debate.

Paul fell short of the record for a Senate filibuster, which is still held by Sen. Strom Thurmond, who spoke for 24 hours and 18 minutes in 1957, when he filibustered a civil rights bill.

Paul took the floor at 11:47 am and finally gave it up around 12:40 am on Thursday. 

By my numbers, Paul's filibuster may be the ninth longest in Senate history.

It probably won't be enough to stop the President's CIA nominee, who could get a vote as early as Thursday.