In a May 1 syndicated column, conservative pundit and MSNBC political analyst Pat Buchanan blamed the April 16 shootings at Virginia Tech on lax U.S. immigration policies, stating that gunman Cho Seung-Hui “was among the 864,000 Koreans here as a result of the Immigration Act of 1965, which threw the nation's doors open to the greatest invasion in history, an invasion opposed by a majority of our people.” In the column -- titled “The Dark Side of Diversity” -- Buchanan claimed: “Had this deranged young man who secretly hated us never come here, 32 people would [be] heading home from Blacksburg for summer vacation.” He added: “What happened in Blacksburg cannot be divorced from what's been happening to America since the immigration act brought tens of millions of strangers to these shores.”

Buchanan suggested that Cho's actions were not an isolated phenomenon, asserting that “in numbers higher than our native born, some [immigrants] are going berserk here.” He cited only anecdotes to support this claim. A 2007 study conducted for the pro-immigration American Immigration Law Foundation by University of California, Irvine sociology professor Rubén G. Rumbaut found that “for every ethnic group, without exception, incarceration rates among young men are lowest for immigrants, even those who are the least educated and the least acculturated.” His research showed that over the last three censuses for blacks, Hispanics, whites, and Asians, "[a]mong men age 18-39 (who comprise the vast majority of the prison population), the 3.5 percent incarceration rate of the native-born in 2000 was 5 times higher than the 0.7 percent incarceration rate of the foreign-born."

Buchanan wrote that, due to the passage of the Immigration Act of 1965, "[t]hirty-six million [immigrants], almost all from countries whose peoples have never fully assimilated in any Western country, now live in our midst." He later declared: “Since the 1960s, we have become alienated from one another even as millions of strangers arrive every year.”

During the August 24, 2006, edition of CNN Headline News' Glenn Beck, Buchanan described illegal immigrants as a “fifth column” within the United States and claimed that immigration could make the “Southwest” become “like Kosovo is to Serbia” because the Mexican government is “pushing” its citizens into the United States as part of a “reconquista.” In his August 25, 2006, syndicated column, Buchanan compared illegal immigrants to the Goths, a group of Germanic tribes who ravaged the Roman Empire in the centuries preceding the collapse of its western half. Buchanan has also stated that immigration will result in “the balkanization of America,” warned that the Southwest “is going to secede from this country,” and claimed that the influx of illegal immigrants into the United States is “not immigration” but “an invasion” that is “coming not only from Mexico,” but “from the whole world.”

In 2006, Thomas Dunne Books published Buchanan's book State of Emergency: The Third World Invasion and Conquest of America. As Media Matters for America documented, the book contains a number of similar claims about the alleged danger of immigration:

• “This [immigration] is an invasion, the greatest invasion in history.” [Page 5]
• “We are witnessing how nations perish. We are entered upon the final act of our civilization. The last scene is the deconstruction of the nations. The penultimate scene, now well underway, is the invasion unresisted.” [Page 6]
• “Chicano chauvinists and Mexican agents have made clear their intent to take back through demography and culture what their ancestors lost through war.” [Page 12]
• "[W]e are in the midst of a savage culture war in which traditionalist values have been losing ground for two generations." [Page 28]

From Buchanan's May 1 column:

Since the massacre of 32 students and teachers at Virginia Tech, the mainstream media have obsessed over the fact the crazed gunmen was able to buy a Glock in the state of Virginia.

Little attention has been paid to the Richmond legislators who voted to make “Hokie Nation,” a Middle American campus of 26,000 kids, a gun-free zone where only the madman had a semi-automatic.

Almost no attention has been paid to the fact that Cho Seung-Hui was not an American at all, but an immigrant, an alien. Had this deranged young man who secretly hated us never come here, 32 people would heading home from Blacksburg for summer vacation.

What was Cho doing here? How did he get in?

Cho was among the 864,000 Koreans here as a result of the Immigration Act of 1965, which threw the nation's doors open to the greatest invasion in history, an invasion opposed by a majority of our people. Thirty-six million, almost all from countries whose peoples have never fully assimilated in any Western country, now live in our midst.

Cho was one of them.

[...]

What happened in Blacksburg cannot be divorced from what's been happening to America since the immigration act brought tens of millions of strangers to these shores, even as the old bonds of national community began to disintegrate and dissolve in the social revolutions of the 1960s.

[...]

Since the 1960s, we have become alienated from one another even as millions of strangers arrive every year. And as Americans no longer share the old ties of history, heritage, faith, language, tradition, culture, music, myth or morality, how can immigrants share those ties?

Many immigrants do not assimilate. Many do not wish to. They seek community in their separate subdivisions of our multicultural, multiracial, multiethnic, multilingual mammoth mall of a nation. And in numbers higher than our native born, some are going berserk here.