Nothing more easily elicits roars of assent across a good slice of the political spectrum than the hoarse alarums that wave after wave of brown-skinned illegals continually flood across the border, plunging neighborhoods and whole cities into an inferno of crime, overwhelming cops and prosecutors, clogging the justice system, cramming the prisons.

Lou Dobbs is pondering a political run powered by a thousand pop-eyed commentaries catering to this fear. “A third of the prison population in this country is estimated to be illegal aliens,” he shouts. Glenn Beck screams about “an illegal alien crime wave.” The panic is by no means confined to the nutball right. Senator Jim Webb of Virginia, launching his commendable plan for a National Criminal Justice Commission last year, invoked the specter of organized Mexican gangs that supposedly threaten “hundreds” of American cities. “There are an estimated 1 million gang members in the United States, many of them foreign-based,” Webb wrote. “Every American neighborhood is vulnerable. Gangs commit 80% of the crime in some locations. Mexican cartels, which are military-capable, have operations in 230+ U.S. cities.”

It’s all nonsense. There’s no crime wave swollen by brown gangbangers to city-destroying proportions. If you want a lucid walk through the data you can turn to… The American Conservative, whose March issue features a cover story by the magazine’s publisher, Ron Unz. There’s a photo of a tattooed gangbanger, and the title “HisPANIC,” then the subtitle: “The Myth of Immigrant Crime.”

Yes, this is the magazine co-founded by Pat Buchanan, whose physical form I last clapped eyes on at the Republican convention in the Houston Astrodome in 1992, roaring to a climactic fist-shake against the black and brown hordes who had recently rioted in Los Angeles: “We must take back our cities, and take back our culture, and take back our country!”

Unz comes to statistical analysis of populations and crime data with decent credentials–he majored in theoretical physics at Harvard, then went on to physics graduate study at Cambridge and Stanford before swerving into very successful software work on Wall Street and now a busy life in Silicon Valley, fostering ideas on both sides of the political aisle. I should add that I count him as a discriminating friend, supportive of left ventures such as CounterPunch as well as The American Conservative, whose tiller he took over in 2007.

At the heart of Unz’s essay is the matter of age-weighting. Most serious crime is committed by young males, especially those between 18 and 29. Now, the age distribution of Hispanics and whites in the overall population is markedly different. The median age for Hispanics is around 27; for whites it’s above 40. But to get useful comparisons you need to look at the relative criminality of Hispanics and whites of the same age; you need to sift out immigration-related offenses (more than half of all federal prosecutions) from state-prosecuted crimes such as robbery, rape, murder, burglary, assault and theft; you need to review comparative data state by state, since there are very significant regional differences in the way justice systems are administered, hence significant variations in incarceration rates.

Unz’s bottom line: “Hispanics have approximately the same crime rates as whites of the same age.” Since poverty and crime have an intimate connection, and since America’s Hispanics are advancing economically, the Hispanic crime rate will most likely drop more. An important further point: Unz uses Census figures for all the states, with a total estimate in 2008 of around 45 million Hispanics. But there’s a widespread view that illegal immigrants are significantly undercounted. So if there are, as some “brown tide” scaremongers allege, 25 million unreported Hispanic illegals above Census numbers, then the true Hispanic crime rate is 35 percent lower than Unz estimates. Almost beyond the shadow of a doubt, white crime rates nationwide are significantly higher than Hispanic ones. Senator Webb needs to refocus his Threat Assessment.

But what about Los Angeles, allegedly the dystopian HQ of immigrant crime, half Hispanic in population, many of them poor and illegal? All crime rates in LA, Unz explains, have been dropping for two decades. Homicides plunged 18 percent last year. Violent crime is roughly the same in LA as in Portland, Oregon, the whitest major city in America, the same as it was in the lily-white LA of the early 1960s. But the gangs? Ah, yes. You see, the feds dole out hundreds of millions each year for gang prevention. Pay a city to find a gang problem and the city will oblige.

Unz had a question for me: “Pro-immigrant advocacy organizations spend hundreds of millions of dollars each year in this exact subject area. So if my theories were correct or even just remotely plausible, wouldn’t such a vast army of paid researchers have long since discovered the same evidence and blasted it out to the four corners of the earth via a very supportive mainstream media?”

My answer: remember that mainstream NGO liberalism–starting with Rockefeller and particularly saturating every environmental foundation–is built on the bedrock of demographic panic about the pullulating poor, particularly the brown and black and yellow hordes. Every billionaire setting up his foundation almost invariably has population control in his mandate. Shoulder to shoulder with hysteria about immigrant crime waves rides fear of the fecund darker races. So I think we can surmise an instinctive racist bias among foundation liberals, their likely belief that Hispanics do commit more crimes and hence their desire to steer clear of all data that they fear might ratify this instinct.