“Remember Domino’s finally admitted they had bad crust?” he asked, drawing chuckles as he tried to draft an analogy to how Republicans should adapt. “We need a different kind of party,” he said, noting that Republicans “have to either evolve, adapt or die.”

Saying the nation’s intelligence apparatus was “drunk with power,” he said that warrantless domestic surveillance should be a matter of concern to everyone.

“I’m not here to tell you what to be,” Mr. Paul told the crowd of several hundred, most of them students taking a break between classes. “But I am here to tell you, though, that your rights, especially your right to privacy, is under assault.” It was an attentive crowd. There were no disruptions or protesters with hectoring signs. At least one person was wearing a Ron Paul T-shirt. The speech was the latest test of Mr. Paul’s experiment to see whether a conservative Republican with a less rigid adherence to the party line can appeal more broadly.

More than most of those Republicans considering a run for the party’s 2016 presidential nomination, Mr. Paul has spent a considerable amount of time courting African-Americans and Hispanics with a message of inclusion and an insistence that his party must drastically change or risk alienating minorities for a generation or more. He has also tested out his free-market economic policies on audiences in traditionally Democratic but economically depressed communities like Detroit. And some Republicans say he is targeting one of the party’s potential growth wings, that of younger, libertarian-leaning voters.

His appearance was another example of his willingness to embrace risk. Few college campuses are as associated with the American left as Berkeley is, and it has often been a caldron of liberal discontent, better known for featuring the anti-Vietnam speeches of Dick Gregory and Dr. Benjamin Spock than for hosting a man elected to the United States Senate on the energy of the Tea Party.

“It’s a bold choice,” Brendan Pinder, a junior who is president of the Berkeley College Republicans, said of Mr. Paul’s decision. “Coming to Berkeley does make a statement.”

Robert B. Reich, the former labor secretary in the Clinton administration who is now a professor of public policy at Berkeley, was walking around the auditorium before the speech and remarked that Mr. Paul had chosen a safe topic.