The bigger the infestation, an exterminator will tell you, the harder the pest is to eliminate.  Thus it is with illegal aliens, and one recent event illustrates that the infestation is so pervasive, it may be well-nigh impossible to stop.

That event was a speech at the University of North Carolina in early April by former U.S. Rep. Tom Tancredo.  Tan-credo, who was briefly a GOP presidential candidate in 2008, went to UNC at the invitation of Youth for Western Civilization, a new conservative student organization springing up on college campuses.  The usual suspects used the usual intimidation and violence to stop his speech.

Police had to remove protestors who carried a banner with a typically leftist and infantile slogan: “No Dialogue With Hate.”  Having ejected the cretins, police pepper-sprayed the mob of about 30 campus leftists.  The acrid mist didn’t quite convince them, so the cops brandished Tasers.  That calmed things down.  Don’t tase me, bro!

Still, all was not well.  During Mr. Tancredo’s speech, two more protestors unfurled a banner emblazoned with more leftist treacle: “No One Is Illegal.”  Mr. Tancredo himself tried to stop them in what became a tug of war with the banner, but alas, the situation quickly deteriorated until a student outside the room shattered a window by pounding on it.  Police rushed in to rescue Tancredo.

“We shut him down; no racists in our town,” the budding Kampfbunders proclaimed.  “Yes, racists, we will fight / we know where you sleep at night!” they shouted.  Another of the young kooks unbosomed this risible reflection on academic freedom: “He was not able to practice his hate speech.  You have to respect the right of people to assemble and collectively speak.”

This is the kind of schizophrenia colleges create these days, but in any event the brownshirt beat-down is nothing new.  Shouting down conservative speakers has long been a weapon in the arsenal of the campus left, mostly owing to the ideas of Marxist philosopher Herbert Marcuse.  But rather more worrisome is the reason the protestors went cuckoo: Tancredo was giving a speech about in-state tuition for illegal immigrants.

Inasmuch as the leftist protestors, or their parents, are subsidizing that tuition, you’d think they might want to learn something about it.  Not so.  Not only didn’t they want to learn anything about it; they didn’t want anyone else to learn anything about it.  So they shut down the speech.  What a long way the left has come from the 60’s.  Your average campus radical used to be troubled by wars and imperialism and occupied with burning brassieres.  Now, aside from legalized buggery, it’s illegal immigrants.  Such is the power of the illegal-alien lobby.  With its own militant campus activities sponsored by flatly racist groups such as MEChA, it is now an entrée on the full menu of leftist causes.

Consider these data from the U.S. Census Bureau, crunched and analyzed by the Pew Hispanic Center.  Although the illegal-alien population has stabilized at about 12 million nationally, having grown to that level between 1990 and 2006, in some states it has increased dramatically since 2000.  In Virginia, that population doubled.  Frighteningly, illegals are now 4 percent of the U.S. population and 5.4 percent of the U.S. workforce.  The children of illegal aliens—some citizens, some not—make up 6.8 percent of America’s elementary- and secondary-school students.  As well, 6.8 percent of K-12 students nationwide have at least one illegal parent.  In five states, the figure is 10 percent; in another five, the number exceeds 7.5 percent.  And 73 percent of the children of illegals are citizens because they were born here.

That snapshot from Pew offers an idea, again, of the burgeoning infestation that may soon grow, if it hasn’t already, beyond our ability to stop it.  Campus radicals and the left in general have added illegal aliens to their agenda, even as both political parties ignore them.  The Democrats ignore them because they give them votes; the Republicans, because they offer cheap labor.  Both parties are helping leftist cultural elites accomplish their goal of undermining the ethnic and linguistic core of the country.

So now, a former congressman cannot speak about a subject of pressing concern to taxpayers because a vicious, totalitarian, and potentially violent mob stopped him.  The end approaches.