"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."