Sen. Rand Paul's 13-hour filibuster on the Senate floor has rallied the fledgling Tea Party movement from a months-long slump and highlighted the schism between those brassy conservative newcomers and their Republican Party elders.

"What a night," Tea Party Express Chairwoman Amy Kremer said after Paul's filibuster, which began Wednesday about noon and ended about 1 a.m. Thursday. "He has definitely energized the base in a way that it hasn't been energized in a long time."

Paul pledged to "speak until I can no longer speak" to prevent a vote on the nomination of John Brennan to head the CIA and lashed out at the Obama administration's possible use of drones on U.S. soil. Fourteen GOP senators, many of them affiliated with the Tea Party, came to the Senate floor to help Paul, R-Ky., maintain the filibuster, including Sens. Ted Cruz, R-Texas, Mike Lee, R-Utah, and Tim Scott, R-South Carolina.

Until Paul's appearance, the Tea Party's popularity appeared to be waning. Republican leaders pushed Tea Party lawmakers to the sidelines during budget negotiations with President Obama. After a very successful 2010 election, the Tea Party took a beating in the 2012 contests. And pollsters found that fewer and fewer people were affiliating themselves with the movement.

But Paul's filibuster attracted huge support on social media sites, from conservatives and liberals, and some believe it could mark a comeback for the movement.

"This is a big deal," said Jason Pye, editor-in-chief of, a libertarian blog that follows the Tea Party.

Hours after the filibuster ended, however, some of the Republican Party's old guard, including Sens. John McCain of Arizona and Lindsey Graham of South Carolina, both of whom have had decades-long careers, took to the floor and bashed Paul's action as "ill-informed" and "ridiculous."

But by Thursday afternoon, Paul's filibuster had forced Attorney General Eric Holder to assure the Senate in writing that the Obama administration would not use drones to kill American noncombatants on U.S. soil. Many considered it a significant victory for Paul and the civil liberty-focused Tea Party. By night's end, 40,000 new followers had signed up for Paul's Twitter feed.

The Senate halls were buzzing, too. Brennan was confirmed as the new CIA director Thursday, Senate aides noted, but only after the White House, in a rare move, responded quickly to Paul's question about drone strikes.

There was a sense of excitement over the new young Tea Party Turks besting the old bulls.

"There couldn't have been a starker contrast between the new leadership of Rand Paul, Mike Lee and Ted Cruz and the old guard of McCain and Graham," noted one GOP aide.

McCain defended his criticisms of Paul, telling The Washington Examiner that the Kentucky lawmaker's opposition to drones would limit the president's power to stop terrorists.

"I think the whole argument, if we went that way, would threaten our national security," McCain said.

But Paul told The Examiner that McCain is wrong and that the public backs his efforts to curb government overreach, a central Tea Party tenet.

"He's dismissive of something that involves the discussion of whether the Fifth Amendment applies to American citizens," Paul said. "And I consider that to be a very important issue."