Paul often recycled arguments as he continued, referring to one of several binders at his desk, or notes passed on occasion from an aide.

While Paul was speaking, his office was posting messages on his official Twitter page. Cruz, in his second trip to the Senate chamber, read some of the supportive messages others had posted on the social networking site, using the hashtag #standwithrand. The National Republican Senatorial Committee sent an email to supporters soliciting online contributions in his name.

Paul first appeared ready to yield the floor after 7 p.m., offering to allow a vote to occur on Brennan if senators would agree to his request for a resolution expressing the sense of the Senate that drone strikes on U.S. soil violated citizens’ right to due process.

Sen. Richard J. Durbin, the second-ranking Democrat, objected while promising to hold a hearing on drone policy. Paul opted to continue speaking instead.

Paul remained standing the entire time, using the occasional breaks to amble about to stretch his legs while a colleague posed a question to him.

As afternoon turned to evening, Paul’s body language revealed the physical toll his effort was taking. At one point, he spoke while chewing on jelly beans from a packet delivered by an aide.

Otherwise, the Senate chamber remained largely empty for most of the day, save for a rotating group of tourists in the gallery and less-tenured senators who cycled through in the chair of the presiding officer.

Each hour, a Senate stenographer would come to replace another near Paul’s desk, dutifully recording every word of his remarks for the official record.

As midnight approached, additional senators came to the floor. So too did a handful of members of the House of Representatives, who sat in the rear of the chamber.

Before Paul finally yielded, he joked that he had hoped to continue for another 12 hours to break the all-time record for a filibuster, held by Strom Thurmond.

But, he joked, "I've discovered that there are some limits to filibustering, and I'm going to have to go take care of one of those in a few minutes."

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michael.memoli@latimes.com

Twitter: @mikememoli