Sen. Rand Paul’s almost 13-hour filibuster generated a massive amount of attention from conservative activists Wednesday, and many were asking why Minority Leader Mitch McConnell wasn’t on the floor cheering him on.

Paul admitted on CNN that he declined to notify his fellow Kentucky Republican or Senate Majority Leader Harry Reid, D-Nev., about his spontaneous plan to hold up Senate action on the nomination of John O. Brennan to be director of the CIA. But grass-roots conservatives helped push behind the scenes to get more Republican senators to join the protest of the Obama administration’s drone program.

A Twitter hashtag went viral, with #StandWithRand trending worldwide, including in far-off spots such as Tehran, the capital of Iran.

“Where is Rand Paul’s fellow Kentucky Senator? Watching Ashley Judd movies?” influential conservative blogger Erick Erickson tweeted at 9:22 p.m., taking a jab at McConnell and the film star who may challenge him in 2014.

Of course, McConnell was bound to have been criticized for his response to the Paul filibuster, regardless of whether he sat on the floor for the entire thing, given his unpopularity among a cadre of vocal tea-party-inspired conservatives.

A McConnell aide says the leader was tracking the events unfolding on the floor throughout the evening, and he eventually did join in — albeit in the eleventh hour of the filibuster — announcing he would oppose limiting debate on Brennan. Brennan’s nomination was the target of Paul’s filibuster, as he sought an answer from Attorney General Eric H. Holder Jr. about the use of drones to target Americans within the United States.

A McConnell aide said the minority leader had already made the decision to oppose Brennan and had communicated his concerns and his position privately, but the announcement on the floor generated the attention and added some heft to Paul’s efforts.

On Thursday, Holder acceded to Paul’s demands and sent him a letter that said the president cannot use drones to kill Americans on U.S. soil. That led Paul to drop his objections to a vote on Brennan, who was confirmed shortly thereafter.

The political import and effect of McConnell’s late-night support of Paul is expected to be negligible back home in the Bluegrass State. In Kentucky, where the disdain for President Barack Obama remains potent, McConnell’s opposition to Brennan can’t hurt. But among the conservative grass roots and within the local tea party infrastructure in the state, the minority leader’s support of Paul won’t move the needle, Republican political operatives of all stripes said.

“I think the symbolism of that late-night stand is lost on just about everybody,” said conservative activist and Kentucky GOP consultant David Adams. Adams managed Paul’s successful Senate primary campaign in 2010 against a McConnell-backed candidate.

“The people who just don’t like [McConnell] are not going to dislike him less because of that and those who are supportive of him are going to stay supportive of him, for now,” Adams added.

McConnell is potentially vulnerable to a challenge from the right in his 2014 re- election bid, in large part because he is viewed by some tea-party-inspired conservatives as not sufficiently pure and as the party establishment. But for now, that threat appears relatively minor despite his unpopularity. Much of the focus in Kentucky political circles has been on Judd, a Democrat who is mulling a 2014 bid against him.

“If there are some hard-core tea party people who don’t like Mitch, we’re under no illusions that this is gonna change that,” one Kentucky-based McConnell ally said.

Of course, McConnell is serving two masters in his current role: the people of Kentucky and the Senate Republican Conference. That tension was on display Thursday when McConnell declined on a conservative radio talk show to directly criticize Sens. John McCain, R-Ariz., and Lindsey Graham, R-S.C., after the duo took to the floor to slam Paul’s drone premise.

Their vociferous opposition to Paul’s effort also made the two national security hawks the target of opposition Thursday. Campaign for Liberty, the 501(c)(4) political organization of Paul’s father, former Rep. Ron Paul, R-Texas, was among those encouraging GOP senators to join in the effort.

“We’re not sure why it took many Senate Republicans so long to stand with Senator Paul, but we are pleased that the grassroots support by Campaign for Liberty members and other liberty-minded individuals eventually led many Senators to go on the record on the issue of drones,” spokeswoman Megan Stiles said in an email. “It’s no surprise that many of the Senators joining the filibuster were freshmen.”

Relative newcomers Mike Lee of Utah and Ted Cruz of Texas were among the first to join Paul on the floor.

McCain and Graham were among the Republican senators dining with President Barack Obama on Wednesday evening, and unlike some others in attendance, they did not return to the Senate floor late Wednesday night to back up Paul’s effort.