Warnings from top Republicans on the threat posed by the Islamic State of Iraq and Syria sure make it seem like the terrorist group is already carrying out a plot to invade the U.S.

Kentucky Sen. Rand Paul insisted earlier this month that the U.S. must secure its borders to prevent “ISIS infiltration.” In August, Texas Gov. Rick Perry warned there was a “very real possibility” that the group had already entered the U.S. through the southwestern states. Arizona Rep. Trent Franks just this week claimed ISIS is currently operating out of Cuidad Juarez, Mexico – not just in the Middle East. Last Wednesday, former Massachusetts Sen. Scott Brown said terrorists are “actually coming through the border right now.”

“… They are urging attacks on the United States of America. And there is a great concern that our southern border and our northern border is porous and that they will be coming across.” Sen. John McCain (R-Ariz.)

For weeks, top lawmakers have stoked fears of a potential terrorist takeover along the southwestern states, casting doubt that the Obama administration is equipped to ensure national security along the border. And though experts and administration officials have dismissed the accusations as lacking credibility, Republicans’ border panic over imminent terrorist attacks is nothing new.

Long before ISIS was even formed, conservatives linked Islamic groups to the immigration debate to gin up calls for stronger border enforcement and to buoy support for heightened military action.

Take Perry’s arguments, for example, which are almost a carbon copy of accusations he made during a 2011 presidential debate. At the time it was groups like Hamas and Hezbollah – even Iran – that Perry claimed were coordinating to infiltrate the U.S. from Mexico. That same year, fellow GOP presidential candidate Rick Santorum said a tighter border would fend off “jihadist training camps in South America.” And back in 2007, an ad for Tom Tancredo’s presidential campaign depicting images of bloody attacks around the world warned the U.S. must crack down on the border in order to prevent a terrorist bombing, a view the anti-immigrant Republican apparently continues to hold today.

PHOTO ESSAY: War Torn Iraq Facing Massive Refugee Crisis

Though the enemies may change, the central fears of an imminent terrorist threat remain the same. Conservatives today remain fixated on the idea that the “porous” U.S. border could allow Islamic militants to slip through the cracks. Arizona Sen. John McCain has even said it’s not just Mexico that could serve as a gateway for terrorists – we should be worried about Canada, too.

“There is Twitter traffic right now and Facebook traffic, where they are urging attacks on the United States of America,” McCain said of ISIS this week on CNN. “And there is a great concern that our southern border and our northern border is porous and that they will be coming across.”

The Obama administration meanwhile has said repeatedly that any connections between ISIS and terrorist plots on American soil are false. In authorizing military airstrikes against ISIS last week, President Obama acknowledged that the U.S. had not detected any specific plans of attack against the homeland, yet he also insisted that country’s security relied on the public’s willingness to take military action.

Close video Beating the drums of war at Senate hearing The top US military commander has refused to rule out boots on the ground in Iraq and Syria - and has The New York Times debunked the myth of ISIS on the Mexican border? Chris Hayes discusses. share tweet email Embed

Department of Homeland Security Secretary Jeh Johnson reiterated that point during a speech before the Council on Foreign Relations last week.



“Though we know of no credible information that ISIL is planning to attack the homeland at present, we know that ISIL is prepared to kill innocent Americans they encounter because they are Americans,” Johnson said, using an alternate acronym for the group.

As the Republican rhetoric of panic mounts, so do the resources and funding for security along the southwest border. According to the Migration Policy Institute, a non-partisan think tank, the U.S. spent about $18 billion on immigration enforcement in the 2012 fiscal year, more than all other law enforcement agencies combined. Meanwhile the White House boasts of more than doubling the number of Border Patrol boots on the ground, from roughly 10,000 in 2004 to more than 21,000 in 2011.

Fears of an imminent terrorist attack along the border are also starting to trickle down to the local level. A Texas sheriff this week said officers found “Muslim clothing” and “Quran books” at the border, proof that Muslims were “being smuggled into the United States.” The sheriff had also previously claimed that ISIS established a foothold in Mexico, a threat to nearby El Paso, Texas.

“If they show their ugly head in our area, we’ll send them to hell,” Gary Painter, sheriff of Midland County, said Monday on Fox News. “I would like for them to hit them so hard and so often that every time they hear a propeller on a plane or a jet aircraft engine that they urinate down both legs.”

“When you do that, then you’ve accomplished a lot,” he said.

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