The GOP's "Rule 40(b)
" requires candidates win the "support of a majority of the delegates from each of eight or more states" in order to have their named placed on the nominating ballot. The raised threshold -- it had previously been a plurality from five states -- helped to prevent Paul's supporters from upstaging or distracting from the presumptive nominee, Mitt Romney, on national television.
"They did not want my name to come up and so they changed the rules because we had the votes," Paul told CNN "At This Hour" anchors Kate Bolduan and John Berman. "We had the numbers to allow my name to be put into nomination, but they wouldn't do it."
Four years later, the same establishment figures who spearheaded the 2012 rules changes are facing a different kind of challenge: Donald Trump. But this time around, the requirement threatens to undermine a late effort to derail the billionaire front-runner.
"I think it's a bit of an irony and they deserve the problem," Paul said. "They're terrified of competition, and now the establishment has competition that really looks strong and there's a lot of people behind Trump. So this is a big problem for them."
The issue could come to the fore if Trump fails to win the 1,237 delegates required to clinch the nomination before the July convention in Cleveland. But with Ted Cruz and John Kasich at risk of not meeting the eight-state majority minimum, the first fight of the 2016 convention could turn on a decision whether to scale back or remove the rule.
Former Arkansas GOP rules chairman Tom Lundstrum sat on the committee four years ago and opposed the changes. He is running to be a state delegate for Cruz in 2016.
"I don't spend a lot of my time trying to finagle outcomes and screw people," he told CNN. "But there are apparently a lot of people out there who do. In 2012, the Romney campaign had a Washington attorney down there trying to make all sorts of changes that were not necessary. And several of them were quite offensive to what I'd call the grassroots electorate. ... They were trying to blunt any gains made by Ron Paul. It was ridiculous."
Paul said he took no pleasure in the GOP's current conundrum, but did suggest their eventual nominee could face a third-party general election challenge.
"It will probably go to the floor, but I think Trump is going to win and I wouldn't be surprised, if that happens, that you're going to see another individual running, a third-party candidate," he said. "Somebody that's going to be supported by the establishment-type Republicans and those who can't control Trump."