Bush admitted in previous interviews and again during Wednesday's Republican presidential primary debate smoking marijuana while attending the prestigious Phillips Academy in Andover, Massachusetts.
"He didn't go to jail," Paul told students at the University of Nevada-Reno on Thursday. "Why? Because he was rich, and he was elite, and he was going to a very special school."
Paul said he didn't begrudge Bush's education, but said that Bush supports policies that disproportionately result in minority and lower-income young people going to jail for lengthy sentences.
"What I do have a problem with is he still wants to put kids in jail for marijuana," Paul said. "What I was upset with Jeb Bush was his hypocrisy."
Paul said at the debate that he advocates for the federal government to be less involved in regulating and penalizing drug use, and that he is seeking policies that would incarcerate people for marijuana far less.
It's a common refrain for him on the campaign trail as he espouses small-government, libertarian principles.
"If a white kid is caught with it, and they're from a well-to-do family, they get a good lawyer, and they don't go to jail," Paul said.
After Paul called him out on it during the debate Wednesday, Bush said he admitted to smoking weed, but disagreed that the answer was to crack down on drugs less.
"We have a serious epidemic of drugs that goes far beyond marijuana," Bush said, citing heroin problems in New Hampshire. "It is appropriate for the government to play a consistent role" in areas like treatment and prevention, Bush added.
He also pushed back on Paul's assertion that he was being a hypocrite.
"I don't want to put poor people in jail, Rand," he said.
Bush's campaign did not immediately offer a response to Paul's renewed line of attack on Thursday when asked by CNN.