Sen. Rand Paul (R-Ky.) criticized what he called the growing militarization of local police forces in an article published on Time’s Web site. (Molly Riley/AP)

The killing of 18-year-old Michael Brown by a police officer in Ferguson, Mo., has produced a rare and surprisingly unified response across the ideological spectrum, with Republicans and Democrats joining to decry the tactics of the city’s police force in the face of escalating protests.

Most notably, the reactions reflect a shift away from the usual support and sympathy conservatives typically show for law enforcement in such situations. Although possibly unique to the circumstances of the events in Missouri this week, the changing reaction on the right is clear evidence of a rising and more vocal libertarian wing within the Republican Party.

No better sign of that came Thursday than in an article by Sen. Rand Paul (R-Ky.) published on Time’s Web site.

“If I had been told to get out of the street as a teenager, there would have been a distinct possibility that I might have smarted off,” he wrote. “But, I wouldn’t have expected to be shot.”

In his piece, Paul criticized what he called the growing militarization of local police forces. “There is a legitimate role for the police to keep the peace,” he wrote, “but there should be a difference between a police response and a military response.”

The response by law enforcement to protesters in Ferguson, Mo., is being criticized for its level of force and use of military-style equipment. We've labeled the weapons and gear being used by police in these photos from Ferguson. (Tom LeGro and Thomas Gibbons-Neff/The Washington Post)

Paul also bluntly pointed to the role that race continues to play in law enforcement. “Anyone who thinks that race does not still, even if inadvertently, skew the application of criminal justice in this country is just not paying close enough attention,” he wrote.

Stuart Stevens, a Republican strategist, said, “It’s an interesting left-meets-right dynamic, and probably Rand Paul is at the center of it.”

Those people alarmed by the militarization of local police, he said, are the same people troubled by the widespread surveillance programs of the National Security Agency or the increasing use of drones as military weapons.

Paul is a prospective 2016 presidential candidate and the leading proponent of libertarian philosophy among elected officials. In Ferguson, he has found circumstances almost tailor-made to advance his worldview. In doing so, he continues to set himself apart from others in the Republican Party with the hope of expanding the party’s coalition and advancing his own political future.

In this case, he blames the militarization of local police on big government and especially Washington’s willingness to provide such materiel to local communities. His comments on race mark another moment in which he is trying to show an openness to the issues affecting African Americans that sets him apart from others in his party.

John Weaver, a Republican strategist, said in an e-mail: “There is a growing concern across the country — and finally across demographic and ideological lines — of the militarization of local police, the often quick escalation in lieu of law enforcement defusing a situation, and the erosion of guaranteed rights under the Constitution. The growing libertarian wing of our party is pushing, rightfully, in this direction.”

The images of police in riot gear, with armored vehicles and heavy weaponry, firing a tear-gas canister at an Al Jazeera camera crew (and then putting their lights and camera onto the ground after the crew fled in terror) have drawn alarming reactions from the left and the right.

1 of 100 Full Screen Autoplay Close Aug. 15, 2014 Aug. 14, 2014 Aug. 13, 2014 Skip Ad × Aftermath of the Ferguson, Mo., shooting View Photos Protests and police action roil the community outside of St. Louis after police killed unarmed black teenager Michael Brown on Saturday night. Caption Clashes intensified as a curfew went into effect after the governor declared a state of emergency. Demonstrators clashed with police Sunday morning after Missouri Gov. Jay Nixon declared a state of emergency and imposed a curfew that went into effect midnight. Demonstrators walk through tear gas launched by police. Carlos Javier Ortiz/For The Wasington Post Buy Photo Wait 1 second to continue.

The rough treatment and detainment of two journalists, Wesley Lowery of The Washington Post and Ryan Reilly of the Huffington Post, has added to the public outrage about the Ferguson Police Department’s handling of the protests over Brown’s killing.

For more traditional conservatives who also might join the presidential race in 2016, the events in Ferguson have been a cause for more careful reactions.

Sen. Marco Rubio (Fla.) said, in part, “I’m very concerned by recent events in Ferguson, including the violence that has gripped that community and the inexplicable jailing of two reporters. As the FBI looks into allegations regarding the police department there, I hope Americans all over the country will voice their opinions through peaceful means and not resort to violence.”

Sen. Ted Cruz (R-Tex.), whose conservatism is far different from Paul’s, walked a careful line in his written reaction that was posted on his Facebook page, balancing what he called the tragedy of Brown’s death with the challenges local police face. He also spoke of the need to protect civil liberties and the right of reporters to cover the news without being intimidated.

Pete Wehner, a White House official during George W. Bush’s presidency and a frequent commentator from the right, highlighted what has changed within the conservative movement. “Libertarians are reacting as one would anticipate, but there are more libertarian voices within the Republican Party today than in the past,” he said in a telephone interview.

But in noting the restrained reactions of more traditional conservatives, he offered this caution to those suggesting that libertarianism is gaining widespread support with the GOP.

“I think a number of people who are conservative are somewhat troubled by the images coming out of there,” he said. “I don’t think that’s indicative of a broader trend among conservatives that is less pro-law enforcement. I think it’s to the specifics” of what has happened in Ferguson.

Stevens predicts a growing audience for these views, particularly among younger Americans. “To be younger and more anti-authoritarian is not unusual,” he said. “More younger voters who are conservative are fine with legalization of marijuana and are fine with gay marriage.”

The strength of the libertarian movement within the Republican Party will be tested more significantly if Paul seeks the presidency in 2016. But at this moment, its advocates are making their voices heard.

“They’re not the largest force by any means,” Wehner said. “But they’re more influential than they have been in the past, and you’re seeing some of that in the reactions to what’s going on in Ferguson.”