Washington (CNN) -- Ron Paul supporters were never that trusting of his son, Rand Paul.
To ardent Ron Paul legions who energized his bid for the presidency around his libertarian principles, Rand Paul reflected a corrupt, business-as-usual political system -- one that asked people to compromise their beliefs in the quest for power.
They saw Ron Paul, a former Texas congressman, rising above that until this week when Rand Paul, the Kentucky senator who is viewed as a potential presidential candidate in 2016, blazed his own path toward their hearts and minds.
He appealed to civil libertarians at their core by challenging the White House nominee to head the CIA, and pushing the Obama administration to clarify -- not once, but twice -- its policy on targeting Americans in counter-terror operations with lethal force.
He threw the faithful a healthy portion of red political meat with a 13-hour filibuster over John Brennan, who was confirmed to the CIA post on Thursday. Brennan was President Barack Obama's chief counter-terrorism adviser.
Rand Paul highlighted his dissatisfaction with the response of the administration to his question of whether it could use a drone to kill Americans on U.S. soil.
The issue resonates with both libertarians on the far right and liberals on the far left by challenging what they consider to be excessive government powers. In particular, Paul sought clarity that only a war enemy -- even if a U.S. citizen -- could be targeted.
His Senate marathon amounted to a libertarian clinic. He quoted libertarian thinkers, emphasized the infallibility of the Constitution and elevated the drone discussion.
And Ron Paul devotees noticed.
"I think this definitely scored him some points," said Gary Franchi, the former chair of the Revolution PAC. "I was getting a lot of messages from people saying 'Wow, Rand is stepping up.' People were really positive about it."
"You have to give credit where credit is due and when someone does something that is clearly fighting for the people's liberty, then regardless of how you feel about that person, you have to take notice," Jordan Page, an ardent Paul supporter and musician for the campaign said. "Rand, these days, is the lone senator standing up against injustice."
During the 2012 campaign, Ron Paul wielded great of influence among a small, but fervent, group of supporters. That passion turned into a fundraising operation that even establishment Republican candidates envied.
When Ron Paul withdrew from the Republican race, more establishment members of the party saw Rand Paul as the inheritor of his father's following. Many in the Ron Paul movement challenged that assumption.
Then Rand Paul began to speak shortly before noon on Wednesday.
"I rise today to begin to filibuster John Brennan's nomination for the CIA. I will speak until I can no longer speak. I will speak as long as it takes," he said.
Blogs dedicated to the liberty movement, a nickname for the Ron Paul campaign, began to blow up with posts about the filibuster.
Radio shows dedicated to Ron Paul scrapped their original programming and covered Rand Paul live.
And the hashtag #standwithRand, a tag that has long been used by libertarian supporters of Rand Paul, began to trend worldwide.
As the hours ticked by, Rand Paul's image among Ron Paul supporters began to change. Even those who ardently opposed Rand Paul during his father's 2012 campaign for president began to soften.
"I was skeptical of Rand Paul from the beginning," said John Bush, a radio host and event organizer for the 2012 Ron Paul campaign. "I appreciate what Rand Paul did last night and I think it sent a very strong message. I have a much higher opinion of him than I did before."
The distrust of Rand Paul stems from Senate votes and decisions he made during the 2012 campaign.
In particular, Ron Paul supporters have pointed to Rand Paul's support of Israel and use of economic sanctions, which they see as overstepping the bounds of American power, as a few of the many reasons they were skeptical of the junior senator from Kentucky.
"The reason why Ron Paul got such a following was because he was pillar with his principles," Mike Salvi, a Philadelphia-based Ron Paul organizer said during the 2012 campaign. "I don't see that in Rand."
Distrust deepened when Rand Paul endorsed Mitt Romney for president last July. Many Ron Paul supporters were still angling for influence at the Republican National Convention and were appalled at the decision.
They felt the senator betrayed his father, cementing long held skepticism.
"Mitt Romney was the straw that broke the camel's back," said Chuck Suter, a Ron Paul supporter who organized events for the presidential campaign.
Suter, who supported Rand Paul throughout Ron Paul's presidential campaign, said that the Romney endorsement was incredibly difficult to defend. He said he took heat from outspoken Ron Paul supporters.
Suter said that Rand Paul's filibuster provided some vindication.
"What last night did for me was it affirmed everything that I had done even when it was hard for me to go out and defend Rand when he endorsed Romney," Suter said. "Last night was the shining jewel of what Rand Paul is all about, to play politics where his father may have not."
Hammered by conservatives on Twitter to #StandWithRand, a number of more establishment senators streamed into the Senate to relieve Paul of his speaking duties and support his cause.
They included Sen. Marco Rubio, who many see as the frontrunner for the 2016 Republican presidential nomination and someone who Ron Paul supporters view as anointed by the establishment.
Senate Minority Leader Mitch McConnell, the personification of "establishment" to many Paul supporters, also took part.
To many Paul supporters, that sort of high-profile backing was icing on the cake.
"Everybody use to say there is no point in working with the GOP because of the mindset that there is no way that you can get Mitch McConnell and Marco Rubio to stand on the ... floor like that," Suter said. "Last night changed things."
And although Paul has said he won't make a decision about a 2016 race until next year, his prolonged filibuster has warmed the mood among once doubtful libertarians.
"I wouldn't mind if Rand Paul was president," said Bush, a voter who said he isn't sure he even support the idea of the presidency. "It would certainly be better than Marco Rubio or Mitt Romney or any of the other goons that the GOP will put up for the nomination."