Presidential candidates Marco Rubio, Jeb Bush, Ben Carson and Bernie Sanders all spoke about strategies to confront terrorism in the wake of the attacks in Paris. (The Washington Post)

For John Courts, the terrorist attacks in Paris that killed at least 132 people provided more evidence of something he has long suspected: Syrian refugees are not to be trusted.

“I think they’re wolves in sheeps’ clothing,” said Courts, 36, a police officer in this industrial town in southeast Texas who attended a political rally for Donald Trump on Saturday. “Bringing those refugees here is very dangerous. Yeah, they need help, but it’s going to bring terrorism right into our front door.”

Courts was relieved a few weeks ago when Trump first promised to kick all Syrian refugees out of the country and not allow any more in. Other Republican presidential candidates have been much more restrained on the issue — until the Paris attacks, which have been blamed on Islamic State terrorists.

Concern about Syrian refugees entering the country has been growing among conservatives for months. They have seen the footage of ruthless Islamic State fighters and read reports of these terrorists beheading Christians, torturing hostages and killing in the name of their faith. They assume that terrorists capable of such acts would pose as refugees. And they are uncomfortable that most Syrians are Muslims — making it all the more difficult to distinguish terrorists from innocent refugees.

Since Friday, several Republican presidential candidates have called for Christian refugees to receive different treatment than Muslim refugees. Former Florida governor Jeb Bush said Sunday that the United States should focus on “Christians that are being slaughtered.” Sen. Ted Cruz of Texas said the country could continue to provide a “safe haven” for Christians but not “refugees that may have been infiltrated by ISIS.”

Louisiana Gov. Bobby Jindal called for sealing off U.S. borders, while former Arkansas governor Mike Huckabee wants to halt the arrival of any refugees from countries with a “strong presence of ISIS or al-Qaeda.” Ben Carson, a retired neurosurgeon who has embraced some of Trump’s views, said Sunday that accepting Syrian refugees is “a suspension of intellect.”

President Obama, like many Democratic leaders, has been more sympathetic to the plight of the millions of Syrians fleeing the violent, years-long war that has consumed their homeland. That has prompted an intense wave of criticism from some Republican voters, including some who have long believed that Obama is Muslim despite his insistence that he is Christian.

“I do not want them here — we don’t know who they are, we don’t know their history, we don’t know if they’re terrorists just being funneled through these other countries,” said Sheila Milbrandt, 49, a paralegal from Sour Lake, Tex., who attended Trump’s Saturday rally. “I don’t like a Muslim in our White House. I don’t like his take on foreign affairs. I think he’s too lax with terrorists.”

The Obama administration has said it wants to host an additional 10,000 Syrian refugees in the coming year — which some liberals argue is not nearly enough. During the Democratic debate on Saturday evening, Hillary Rodham Clinton and former Maryland governor Martin O’Mal­ley said the United States should increase that number to 65,000. Both said those refugees need to be heavily vetted. Sen. Bernie Sanders of Vermont won’t put a number on it.

O’Malley said that these refugees are fleeing terrorism and the United States needs to be “a moral leader in this world.” He noted that, in a country of 320 million, adding 65,000 refugees “is akin to making room for 6  1/2 more people in a baseball stadium with 32,000.”

Lavinia Limon, the president and chief executive of the U.S. Commission for Refugees and Immigrants, said she is surprised that the once-nonpartisan cause of helping refugees fleeing violence has become so politicized. She noted that it takes about three years for refugees to go through stringent security screenings — a process that she doubts terrorists would wait through when there are other ways to get into the United States.

Donald Trump said at a rally in Beaumont, Tex. that "it would've been a much, much different situation" if France had different gun laws and more civilians were armed during a series of deadly attacks in Paris. (Reuters)

“The definition of a refugee is someone fleeing oppression. They’re fleeing terrorism,” she said. “They’ve experienced what happened in Paris on a daily basis.”

Anti-Muslim sentiments related to the Syrian crisis first bubbled up on the campaign trail over the summer, as the influx of refugees in Europe hit a tipping point. Trump was the first to pounce.

“They could be ISIS. I don’t know,” Trump said at a rally in New Hampshire back in September. “Did you ever see a migration like that? They’re all men, and they’re all strong-looking guys. Did you see it? They’re walking and there are so many men. There aren’t that many women. And I’m saying to myself: Why aren’t they fighting to save Syria? Why are they migrating all over Europe? Seriously.”

Such comments are more often found in forwarded e-mails and Facebook rants than the remarks of a presidential candidate. But Trump is a proudly politically incorrect candidate who has questioned Obama’s place of birth and labeled illegal immigrants as mostly being violent criminals. Trump has criticized Obama for agreeing to accept more refugees, and he said German Chancellor Angela Merkel is “insane” for allowing so many refugees into her country.

“This could be the greatest Trojan horse,” Trump said in an interview last month. “This could make the Trojan horse look like peanuts if these people turned out to be a lot of ISIS.”

Trump’s comments on Syrian refugees contain inaccuracies. He has repeatedly said that the United States plans to accept 250,000 Syrian refugees, even though the Obama administration has committed to helping only 10,000. The six-digit figure may trace to the total number of refugees from all countries, not just Syrians, that the United States will admit in 2016 and 2017. (The actual number is 185,000, according to the Obama administration.)

Trump has also said a majority of Syrian refugees are young men of fighting age. The United Nations estimates that of the more than 4 million Syrian refugees living in camps in the Middle East, less than a quarter are men over the age of 18.

Trump’s comments came as validation for activists who have long fought the arrival of refugees — including Joe Newton, a retired law clerk in his 60s who lives in the Atlanta suburbs. Two years ago, Newton became angry when dozens of what he described as Middle Easterners moved into a friend’s neighborhood.

“They had open sewers,” Newton said. “Animals running all over the place. They were doing animal sacrifices. They had horns going off at 6:30, 7 o’clock in the morning, as the call to worship. They had shack-looking buildings with tar-paper roofs. And trash everywhere.”

Newton is angry that taxpayer dollars support refugees who cling to a culture so different from his own. He wants to move all Syrian refugees to a camp in their own country protected by a “brigade of Marines and a few jets.” Early on, Newton said he was labeled as racist and ostracized by Republicans, but he said that in the past few months “people started waking up.”

Newton passed out 2,000 fliers outside a Trump rally in the Atlanta suburbs on Oct. 10. The fliers featured a photo of local Muslim men and boys gathered on a basketball court to pray. The flip side warns in underlined bold letters: “Your Federal and State tax money is being used to bring Middle Eastern Muslims to Georgia without a thorough background check. They have immediate access to all government programs including: food stamps, welfare, health insurance, free cell phones and subsidized rents.”

Inside the rally, Mary Stevens, 70, held a homemade sign reading “No Muslim refugees.”

“I don’t mind taking refugees who are Christian,” said Stevens, who lives in Marietta, Ga., “but the Muslims scare me.”

During that rally, Trump didn’t mention Syrian refugees, and the issue soon faded from his stump speech, only to quickly reemerge last week as Paris came under attack.

Trump opened his Saturday rally at an arena in Beaumont with a moment of silence in remembrance of those killed — and then immediately questioned why the United States would allow refugees to settle here given that one of the terrorists in Paris was found with a Syrian passport.

“And our president wants to take in 250,000 from Syria,” Trump said, as the crowd of about 5,000 booed the president. “We all have heart, and we all want people taken care of and all of that, but with the problems our country has — to take in 250,000 people, some of whom are going to have problems, big problems — is just insane. You have to be insane.”

The crowd cheered. It was a prime example of Trump saying the things that his supporters are thinking, said Kendall Johns, 43.

“I don’t want any of them here,” said Johns, who lives in Beaumont and works at an oil refinery. “I mean, send them to Mexico. Send them to Central America. Send them to South America. I don’t want them here.”

Katie Zezima in South Carolina and David Weigel in Washington contributed to this report.