So we all know about Republican Senate candidate Tom Cotton trying to link immigration policy to national security policy via wild and unsubstantiated “reports” of IS terrorists lurking beyond or crossing the U.S.-Mexican border, with or without first conspiring with drug cartels. And most recently, we’re hearing Republican Senate candidates Scott Brown and Thom Tillis trying to claim that lax “border enforcement” is exposing Americans to Ebola.

Now it may just be, as Kevin Drum has suggested, that this is just word-salad-mixing whereby candidates toss out combinations of words that excite “the base” or upset low-information voters. But there’s another and more obvious way to look at it: Republicans are appealing to an atavistic tendency to think of “the border” as a barrier against all the terrible things in the world Out There, in the benighted lands beyond America. “Sealing” the border–a laughable concept when you think about it–will somehow restore Fortress America, and all the terrorists and diseases and free-loaders and non-English-speakers and socialists and atheists will be kept out the way God intended it. And the crazier and more dangerous the “outside world” becomes, the more making it all go away seems appealing.

Yes, it may be as simple as that.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.