Via Tyler Cowen, David Leonhardt of the New York Times has performed some much-needed fact-checking on CNN’s Lou Dobbs:

The whole controversy involving Lou Dobbs and leprosy started with a “60 Minutes” segment a few weeks ago.

The segment was a profile of Mr. Dobbs, and while doing background research for it, a “60 Minutes” producer came across a 2005 news report from Mr. Dobbs’s CNN program on contagious diseases. In the report, one of Mr. Dobbs’s correspondents said there had been 7,000 cases of leprosy in this country over the previous three years, far more than in the past.

When Lesley Stahl of “60 Minutes” sat down to interview Mr. Dobbs on camera, she mentioned the report and told him that there didn’t seem to be much evidence for it.

“Well, I can tell you this,” he replied. “If we reported it, it’s a fact.”

With that Orwellian chestnut, Mr. Dobbs escalated the leprosy dispute into a full-scale media brouhaha…

Mr. Dobbs argues that the middle class has many enemies: corporate lobbyists, greedy executives, wimpy journalists, corrupt politicians. But none play a bigger role than illegal immigrants. As he sees it, they are stealing our jobs, depressing our wages and even endangering our lives.

That’s where leprosy comes in.

“The invasion of illegal aliens is threatening the health of many Americans,” Mr. Dobbs said on his April 14, 2005, program. From there, he introduced his original report that mentioned leprosy, the flesh-destroying disease — technically known as Hansen’s disease — that has inspired fear for centuries.

According to a woman CNN identified as a medical lawyer named Dr. Madeleine Cosman, leprosy was on the march. As Ms. Romans, the CNN correspondent, relayed: “There were about 900 cases of leprosy for 40 years. There have been 7,000 in the past three years.”

“Incredible,” Mr. Dobbs replied.

Mr. Dobbs and Ms. Romans engaged in a nearly identical conversation a few weeks ago, when he was defending himself the night after the “60 Minutes” segment. “Suddenly, in the past three years, America has more than 7,000 cases of leprosy,” she said, again attributing the number to Ms. Cosman.

To sort through all this, I called James L. Krahenbuhl, the director of the National Hansen’s Disease Program, an arm of the federal government. Leprosy in the United States is indeed largely a disease of immigrants who have come from Asia and Latin America. And the official leprosy statistics do show about 7,000 diagnosed cases — but that’s over the last 30 years, not the last three.

The peak year was 1983, when there were 456 cases. After that, reported cases dropped steadily, falling to just 76 in 2000. Last year, there were 137…

So Mr. Dobbs was flat-out wrong. And when I spoke to him yesterday, he admitted as much, sort of. I read him Ms. Romans’s comment — the one with the word “suddenly” in it — and he replied, “I think that is wrong.” He then went on to say that as far as he was concerned, he had corrected the mistake by later broadcasting another report, on the same night as his on-air confrontation with the Southern Poverty Law Center officials. This report mentioned that leprosy had peaked in 1983.

Of course, he has never acknowledged on the air that his program presented false information twice. Instead, he lambasted the officials from the law center for saying he had. Even yesterday, he spent much of our conversation emphasizing that there really were 7,000 cases in the leprosy registry, the government’s 30-year database. Mr. Dobbs is trying to have it both ways.

I have been somewhat taken aback about how shameless he has been during the whole dispute, so I spent some time reading transcripts from old episodes of “Lou Dobbs Tonight.” The way he handled leprosy, it turns out, is not all that unusual.

For one thing, Mr. Dobbs has a somewhat flexible relationship with reality. He has said, for example, that one-third of the inmates in the federal prison system are illegal immigrants. That’s wrong, too. According to the Justice Department, 6 percent of prisoners in this country are noncitizens (compared with 7 percent of the population). For a variety of reasons, the crime rate is actually lower among immigrants than natives.

Second, Mr. Dobbs really does give airtime to white supremacy sympathizers. Ms. Cosman, who is now deceased, was a lawyer and Renaissance studies scholar, never a medical doctor or a leprosy expert. She gave speeches in which she said that Mexican immigrants had a habit of molesting children. Back in their home villages, she would explain, rape was not as serious a crime as cow stealing. The Southern Poverty Law Center keeps a list of other such guests from “Lou Dobbs Tonight.”

Finally, Mr. Dobbs is fond of darkly hinting that this country is under attack. He suggested last week that the new immigration bill in Congress could be the first step toward a new nation — a “North American union” — that combines the United States, Canada and Mexico. On other occasions, his program has described a supposed Mexican plot to reclaim the Southwest. In one such report, one of his correspondents referred to a Utah visit by Vicente Fox, then Mexico’s president, as a “Mexican military incursion.”

When I asked Mr. Dobbs about this yesterday, he said, “You’ve raised this to a level that frankly I find offensive.”

The most common complaint about him, at least from other journalists, is that his program combines factual reporting with editorializing. But I think this misses the point. Americans, as a rule, are smart enough to handle a program that mixes opinion and facts. The problem with Mr. Dobbs is that he mixes opinion and untruths. He is the heir to the nativist tradition that has long used fiction and conspiracy theories as a weapon against the Irish, the Italians, the Chinese, the Jews and, now, the Mexicans…

Update 6/1 11:05 AM: Reader Joel Wiles points out via email that Leonhardt’s fact-check of Dobbs on the composition of the federal prison system in the article above is itself misleading. Let me try to sort things out.

Leonhardt criticizes statements Dobbs made during a 2003 broadcast. At the top of the show, Dobbs said this:

One-third of the inmates now serving time in federal prisons come from some other country — one-third. The cost to taxpayers, $1.5 billion. Bill Tucker will have the report.

He repeated similar language mid-show, but when introducing Tucker’s segment, Dobbs referred to illegal aliens as “an increasing part of America’s prison population”:

The great American giveaway. Tonight, we focus on illegal aliens. There are now an estimated 10 million illegal aliens in this country; some estimates even higher.

Those illegal aliens are also an increasing part of America’s prison population and its burden to taxpayers. The cost to taxpayers is simply astonishing. Bill Tucker’s here tonight with a report — Bill.

This phrasing is misleading. Dobbs uses the high proportion of non-citizens in the federal prison system, which houses a small percentage of the nation’s prisoners, to suggest (falsely) that the number of non-citizens in the overall prison population is increasing. Viewers may also end up thinking that non-citizens make up a significant proportion of the overall prison population, which is also false.

However, Leonhardt’s fact-check of Dobbs in the main text is bogus:

[Dobbs] has said, for example, that one-third of the inmates in the federal prison system are illegal immigrants. That’s wrong, too. According to the Justice Department, 6 percent of prisoners in this country are noncitizens (compared with 7 percent of the population). For a variety of reasons, the crime rate is actually lower among immigrants than natives.

Note that Leonhardt is comparing apples to oranges — Dobbs was referring to the federal prison system, while Leonhardt presents statistics for the entire US prison population. To actually understand the dispute and see why Dobbs’s statement was misleading, you need to read Leonhardt’s sidebar, which I didn’t originally see (I came to the main article online):

Near the start of his Nov. 4, 2003, program on CNN, Lou Dobbs said, “One-third of the inmates now serving time in federal prisons come from some other country — one-third.” Later, he offered more details: “Coming up, we’re going to take a further look at the impact of illegal aliens. And it is an expensive proposition, particularly in our nation’s prisons. Illegal aliens, those citizens — noncitizens taking up a third of the cells in our federal penitentiaries.”

He also said that illegal immigrants were “an increasing part of America’s prison population.”

Here are the facts, according to the Department of Justice:

¶In 2000, 27 percent of the inmates in federal prisons were noncitizens. Some of these noncitizens were illegal immigrants, and some were in this country legally. In 2001, this percentage dropped to 24 percent, and it continued dropping over the next four years, falling to 20 percent in 2005.

Bottom line: illegal immigrants make up significantly less than a third of the federal prison population, and the share has been falling in recent years.

¶The share of state prison inmates who are noncitizens is much lower. (This is largely because immigration violations themselves are federal crimes.) In 2000, 4.6 percent of inmates in state prisons were noncitizens. This number remained quite steady over the next five years, right around 4.6 percent.

¶Over all — combining federal and state prisons — 6.4 percent of the nation’s prisoners were noncitizens in 2005. This is down from 6.8 percent in 2000.

¶By comparison, 6.9 percent of the total United States population were noncitizens in 2003, according to the Census Bureau.

Dobbs responded to Leonhardt by obscuring the issue further:

We reported that one-third of the federal prison population three and a half years ago were “non-citizens.” The columnist said the number was 6 percent. The exact number of the year in question was 29.3 percent for fiscal year 2001. And by the way, we’re putting up links on our Web site, loudobbs.com, so you can check the numbers for yourself.

But as you can see above, Leonhardt wrote that six percent of all prisoners were non-citizens, not six percent of federal prisoners.

Dobbs did retract the claim that the number of illegal immigrants in US prisons was increasing, however:

I introduced that report three and a half years ago by saying the number of illegal immigrants in our prisons was increasing and the financial burden rising. Well, we had to go back and check, and because our correspondent no longer has his notes to support that statement, that the number of illegal immigrants within a prison population of non-citizens, I have to retract it here tonight, and I apologize to you for the necessity of doing so. But like I said, I do make mistakes.