WASHINGTON — The last time Sen. Rand Paul of Kentucky staged a marathon protest on the Senate floor, over the government drone policy, fellow Republican Sen. Marco Rubio rushed to stand by his side.
This week, Paul tried to recapture that spirit, inveighing for 10.5 hours against the National Security Agency's data collection program — an effort that also attempted to boost his presidential campaign.
Toward the end of the session that went late into Wednesday, Rubio slipped into the chair presiding over the chamber. But he was just watching.
Rubio and Paul are polar opposites on the issue, which could come to a vote today or Sunday, illustrating the Republican schism over the balance between individual privacy and national security.
Rubio once wanted to be at least associated with Paul, who in 2013 was riding a less interventionist mood and garnering loads of attention. Now the Floridian is competing for the GOP presidential nomination and positioning himself as the ultimate hawk — a position solidified by growing public concern over the Islamic State, Iran and general threats abroad.
"You'd be hard-pressed to find two people who disagree more," said Christopher Preble, vice president for defense and foreign policy studies at the Cato Institute, a libertarian think tank.
Paul, who has a strong libertarian streak, and Rubio disagree on how active the United States should be abroad, the level of foreign aid, funding for the military, the diplomatic thaw with Cuba, and so on.
With key provisions of the Patriot Act set to expire at midnight May 31, and the House last week approving a bill that places limits on data collection, Paul seized the opportunity.
"Anytime you give power to government, they love it, and they will accumulate more," he said Wednesday, calling for more substantial restrictions than the House legislation, which passed in an overwhelming bipartisan fashion.
He repeatedly invoked the Fourth Amendment protecting against unreasonable searches and seizure. Earlier this month a federal appeals court ruled that the NSA's phone record collection program is illegal because it was not written into the Patriot Act.
Rubio did not speak Wednesday — he was in the presiding chair by chance, an aide said — but has been a strong defender of the NSA program, calling fears overblown and suggesting any attempts to weaken it could harm Americans.
"There is not a single documented case of abuse of this program," Rubio argued in a May 10 piece published in USA Today. "Internet search providers, Internet-based email accounts, credit card companies and membership discount cards used at the grocery store all collect far more personal information on Americans than the bulk metadata program."
That view is shared by most of the other Republican presidential hopefuls, including Jeb Bush, who told a crowd in Oklahoma on Friday there was "ample evidence" the Patriot Act has protected Americans. Sen. Ted Cruz of Texas, also a candidate, joined Paul on Wednesday, but Cruz's calls for reining in the NSA did not go as far.
"Being commander-in-chief has a different set of skills and expectations and that may be why Rubio's taking a stronger, more traditional Republican stance. He's trying to prove he's got the chops to be president," said Andrew E. Smith, a nonpartisan pollster in New Hampshire.
Still, he added, Paul could use the issue to distinguish himself among a large crop of Republican hopefuls and appeal to a broader base of voters concerned with government intrusion and privacy.
"You don't have to win 50 percent of the vote to win the New Hampshire primary," Smith said.
Paul did not hide the attempt to invigorate his presidential campaign, asking people on Twitter to rally around him and sending out a fundraising email that took an implicit shot at Rubio and others like him.
"Fellow conservative," it read, "we can't simply stand by and watch while Big Government spy state apologists try to gut our freedoms."
Paul likely won't prevail in the Senate, but he did manage to draw attention to an issue that has gotten relatively little notice.
Republican Majority Leader Mitch McConnell is eager to quickly extend the sweeping Patriot Act — first passed after the Sept. 11, 2001, attacks — without changes, saying it is vital to national security.
"Once people start asking questions then the public may say, 'What is it about this particular program that causes concern?' '' Preble said.
He acknowledged politics have shifted toward Rubio's hawkish views but added, "The public is still quite anxious and skeptical of the program."
A Pew Research survey released Wednesday showed that 65 percent of Americans, when asked about the data the government collects for counterterrorism efforts, say there are not adequate limits.
Mary Madden, a senior researcher at Pew, said public support for the data collection program has decreased since Edward Snowden, the rogue former NSA contractor, began to leak details in 2013. Public attitudes have also been shaped by data breaches at companies such as Target and Home Depot.
"The underlying sense is one of vulnerability and loss of control," Madden said, adding, however, that the public is more likely to support the surveillance of foreigners.
That could give Paul footing as he tries to break out of the large pack of Republican presidential hopefuls. Tea party and "liberty" groups were quick to praise him, and joining Paul on the floor Wednesday were a number of Democrats.
Rubio, on the other hand, is trying to make national security a focus of his presidential campaign. While he has mostly hewed to the Republican line since his election in 2010, his rhetoric has grown sharper in the last year or so as he seeks to gain favor with conservatives, some still upset with his role in helping write the Senate immigration overhaul.
During a speech last week before the Council on Foreign Relations, Rubio laid out an aggressive policy that repudiated President Barack Obama's attempts to pull back from the world stage.
"We cannot let politics cloud the importance of this issue," he said, calling on lawmakers to reauthorize the Patriot Act. "We must never find ourselves looking back after a terrorist attack and saying we could have done more to save American lives," Rubio said.
Later that day, the House voted 338-88 to reel in the NSA program. All but four of Florida's 17 Republicans joined the majority.
Contact Alex Leary at firstname.lastname@example.org. Follow @learyreports.