Updated 9:30 p.m. ET, 3/19/2014
(CNN) - Sen. Rand Paul, who's become known for venturing into unfamiliar territory for Republicans, spoke Wednesday at the liberal hotbed of the University of California at Berkeley.
The Kentucky Republican castigated President Barack Obama for his continued support of the National Security Agency's phone metadata collection, saying the President should know better in part because of his race.
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"The first African-American president ought to be a little more conscious of the fact of what has happened with the abuses of domestic spying," Paul said.
"Martin Luther King was spied upon, civil rights leaders were spied upon, Muhammad Ali was spied upon, antiwar protesters were spied upon," he added. "The possibility for abuse in this is incredible. So I don't care if there's never been any evidence of abuse with the (NSA)., they should not be collecting the data."
The domestic data collection program became public after former NSA contractor Edward Snowden leaked the tactic, as well as a hoard of other NSA spying techniques, to the media last year.
In his speech Wednesday at Berkeley, Paul also mentioned the recent controversy surrounding claims that the CIA has been spying on computers used by Senate Intelligence Committee. CIA Director John Brennan responded with a flat-out denial of any wrongdoing.
"I don't know about you, but I'm worried. If the CIA is spying on Congress, who exactly can or will stop them? I look into the eyes of senators and I think I see real fear," he said.
"Maybe it's just my imagination, but I think I perceive fear of an intelligence community drunk with power, unrepentant, and uninclined to relinquish power," Paul said. "I am honestly worried and concerned about who is truly in charge of our government. Most of you have read the dystopian nightmares, the dystopian novels and maybe, like me, you doubted that it could ever happen in America."
Paul announced last month he was suing the Obama administration, demanding that the phone metadata collection be declared unconstitutional and put to an end.
The senator fired up a crowd with his unabashed libertarian views and staunch anti-NSA position earlier this month at the Conservative Political Action Conference, an audience that also voted him as their top pick in CPAC's GOP presidential nomination straw poll.
"If you have a cell phone, you are under surveillance," he said on stage. "I believe what you do on your cell phone is none of their damn business."
Wednesday's event at Berkeley is already sold out, and while it seems an unlikely place for a Republican to traverse, the San Francisco Bay area campus isn't uncharted territory for the Kentucky senator's family. His father, former Rep. Ron Paul, generated a huge turnout when he visited the school in April, 2012.
The elder Paul developed a cult-like following among university students during his last two presidential campaigns. His positions often bucked the Republican establishment and had crossover appeal to some Democrats on issues involving national security, foreign policy and government overreach.
His son is carrying on that torch of libertarianism, but with a more pragmatic approach that seems to be blazing a wider trail as he considers his own presidential bid.
A recent CNN/ORC International poll shows Paul is at the top of a crowded field of potential Republican presidential candidates, with 16% support among Republicans nationwide. While his father proved to be a formidable competitor in the 2012 GOP primaries, the congressman never found himself at the top of a presidential poll.
Rep. Paul Ryan, the 2012 GOP vice presidential nominee, is just one percentage point behind, at 15%, and Texas Gov. Rick Perry, who's considering another bid for the White House, comes in at 11%. Former Arkansas Gov. Mike Huckabee, a 2008 GOP presidential candidate, is the only other Republican tested in the survey to crack double digits.
Paul has been aggressive in calling for a broader GOP in recent months and has taken his message to nontraditional Republican venues, such as historically black colleges. He's also preached his unconventional ideas at GOP gatherings in red states such as Texas and Missouri.
"We need to have people with ties and without ties, with tattoos and without tattoos; with earrings, without earrings," he said at a Republican event in Texas last month. "We need a more diverse party. We need a party that looks like America."
CNN's Paul Steinhauser, Peter Hamby, and Alison Harding contributed to this report.