Presumptive Republican presidential nominee Donald Trump said Sunday that profiling Muslims is "common sense" after the Orlando terrorist attack, but some experts say doing so could be ineffective at best and counterproductive at worst.
"Well, I think profiling is something that we're going to have to start thinking about as a country," Trump said in an interview with CBS' John Dickerson. "Other countries do it, you look at Israel and you look at others, they do it and they do it successfully. And I hate the concept of profiling but we have to start using common sense and we have to use our heads."
Trump did not elaborate on whether he backs profiling solely based on religion or race, or an approach that includes other factors. The campaign did not respond to a request for clarification Monday.
It is the latest of many Trump statements about Islam that have generated controversy, including his vow to temporarily ban all Muslims from immigrating to the U.S.
The interview aired on "Face the Nation" a week after the terrorist attack that killed 49 people in an Orlando nightclub, perpetrated by a gunman who was apparently inspired by ISIS.
Trump had spoken of profiling in a previous interview with Dickerson in December, claiming that people did not report suspicions of the terrorists involved in the San Bernardino shooting because they did not want to appear to be profiling.
Former New York City Mayor Rudy Giuliani, a Trump supporter, told Fox News Monday that investigators always rely on some degree of profiling "based on hard facts that lead to the protection of the public," but he also said doing it based on race or religion is wrong.
On his radio show Monday, conservative Rush Limbaugh noted that Dickerson had brought the issue up, not Trump, but he agreed that profiling would be common sense.
"I guess profiling is only wrong when it might save lives and help protect us from a terror attack," Limbaugh said. "Then we're not allowed to profile. And we're not allowed to profile anybody who might be an illegal immigrant."
Several of Trump's former rivals for the GOP nomination have backed the idea of targeting Muslims for increased scrutiny in the past.
"We need to empower law enforcement to patrol and secure Muslim neighborhoods before they become radicalized," Sen. Ted Cruz said in a Facebook post after the attack in Brussels in March, a proposal that his campaign later softened.
"I would put a big focus on the people who are most likely to commit this kind of activity," former Arkansas Governor Mike Huckabee told Fox News in December. "And if people have been traveling to the Middle East, and there's indications that there is radicalization, you know, then I'd put the focus on them. I wouldn't go put the focus on Tucker Carlson and be afraid that he's going to go crazy on us one day."
"Obviously Muslims would be someone you'd look at, absolutely," former Pennsylvania Sen. Rick Santorum said at a debate in 2011. "Those are the folks who ... the radical Muslims are the people that are committing these crimes by and large, as well as younger males."
If Trump was referring to the kind of religious profiling these other candidates supported, some legal and terrorism experts doubt it would prevent future attacks.
Alan Dershowitz, an attorney, author and former member of O.J. Simpson's defense team, questioned the wisdom of focusing on the race or religion of potential terrorists in an interview with Armstrong Williams.
"No racial profiling, but profiling," Dershowitz said on "The Right Side." "We should profile individuals by their travel records, by their statements, by their Facebook... and we should know more about people that we invite into this country."
He noted that the current terror threat comes from people entering the country with intent to do harm and homegrown extremists self-radicalized on the internet. He said the government needs to get tougher on both of those groups, suggesting that this may include increased surveillance in public places.
In addition to the constitutional concerns raised by singling out a religion for scrutiny, former Department of Homeland Security counterterrorism coordinator John Cohen said there is simply no evidence to suggest the approach would make Americans safer.
"There is no area of law enforcement that benefits from policing strategies that look solely at the race or religion or ethnicity of an individual," Cohen, now a professor at Rutgers, said.
Those characteristics can be helpful to look for in combination with behavioral factors that have been identified in violent extremists, but he noted that some suspects who have been inspired by ISIS were not even converts to Islam.
"What we have learned is that it has much more to do with the psychological and behavioral characteristics of the individual vs their understanding and connection with the ideology espoused by ISIS and al Qaeda," he said.
Some of these factors, such as the need for social connection and meaning in life, have been seen in school shooters and gang members over the last few decades, but Cohen worries that knowledge is not being applied to countering violent extremism.
"In order to deal with a problem, you have to understand the problem," he said, and the government's current approach to fighting ISIS does not reflect a full understanding of the problem.
Cohen recommended conducting a behavior risk assessment similar to what the Secret Services uses to evaluate threats and having some alternative intervention process for potential extremists who have not yet violated the law.
The Institute for Critical Infrastructure Technology recently released a study of the characteristics of "the self-radicalized lone-wolf terrorist." Senior Fellow James Scott, who co-authored the report, argued that there are significant elements that may transcend faith and ethnicity.
"This is definitely something where one self-radicalizes, they become an extremist first, and then they pick the ideology with which to carry out the attack second," Scott said.
The path to radicalization can begin in early childhood with a lack of socialization, mental illness or a dysfunctional and abusive family life, but they have not yet defined their grievances in youth.
"They're a ticking time-bomb when they go into adult years... They're just looking for an ideology that is as perverted and extreme as they are," he said.
This makes them ripe for recruiting by ISIS, al Qaeda, or anti-government terrorist groups. The FBI knows this profile, according to Scott, so they must find a way to thoroughly investigate people who fit it without infringing on their constitutional rights.
"This can be anybody," he said. "This can be a white lady in Brooklyn, a black guy in Wisconsin, a 25-year-old who has a new obsession with guns but a history of mental illness."
Advocates for the American Muslim and Arab communities have pushed back against Trump's focus on Islam.
"It doesn't work and it's discriminatory," said Maya Berry, executive director of the Arab American Institute.
"You can only make the case for profiling if you believe it to be logical to hold an entire class of people to be suspect," Berry said.
She argued that a "lazy" reliance on one specific profile makes it easier for terrorists to send an operative who fits a different profile to launch an attack.
"We want law enforcement to focus on actual criminal behavior," she said.
Abed Ayoub, legal and policy director for the American-Arab Anti-Discrimination Committee, suggested that profiling makes the public less safe.
"Usually the folks that do raise this are out of touch with what methods work," Ayoub said.
He pointed out that Muslim communities are often very vigilant in reporting suspicious behavior, and he suggested that law enforcement policies that vilify and cast suspicion on Islam can damage their trust of police.
"Nobody is saying, 'Hands off, let's not prosecute these guys,'" Ayoub said, but he feels there are other measures authorities could take that would address the real threat more effectively.
Whether it is good policy or not, it is likely good politics for Trump to propose profiling to appeal to his base. Deborah Schildkraut, a professor of political science at Tufts University, said support for measures like profiling increases in the wake of a terrorist attack.
"The more people feel threatened and unsafe, the more they support it," she said.
Republicans generally support it more than Democrats, and the largely white, less educated base that propelled Trump in the primaries is a demographic that is most likely to favor it.
There are risks, though. Schildkraut said Democrats' most effective counter-measure might be to bluntly declare Trump's plan to be racist.
"If you call it out and say, 'Hey, this is a racist policy,'" she said, some voters will rethink their support to avoid associating themselves with the perceived racism.
According to Cohen, politicians make a mistake when they treat violent extremism as a danger specifically coming from Islam. There is a tendency in Washington, D.C. to define problems in the most simple, black-and-white terms, but race and religion are only one element of a very complicated threat.
"Unfortunately, this is a problem that has a lot of gray area," Cohen said.