Mr. Paul, Kentucky, revealed his vote in an interview with Politico.
“I’m a no,” he told the publication. “He’s been the chief advocate for warrantless surveillance of U.S. citizens. I think that the Fourth Amendment should protect your phone calls and bank information. People shouldn’t be allowed to look at it without a warrant.”
Mr. Paul’s decision does not come as a surprise. In December, he told NBC’s “Meet the Press” that Mr. Barr’s support of the Patriot Act was “very, very troubling.”
Also, Campaign for Liberty, a conservative activist group founded by his father, former Rep. Ron Paul, Texas Republican, had railed against Mr. Barr’s nomination.