In the fall of 2009, Lou Dobbs left CNN amid a furor over his embrace of conspiracy theories about President Obama's birth certificate. It looks like he didn't learn much from that experience.

Friday, a graphic on Dobbs' Fox Business show cited the right-wing website American Thinker as the source for a figure about Michelle Obama's vacations:

American Thinker has published the writings of Jack Cashill, a shameless birther conspiracy theorist, and hosted Cashill's suggestion that the president's father was not Barack Obama Sr., but Frank Marshall Davis, a writer and labor activist.

Aside from other instances of birther nuttiness, American Thinker has also published prominent white nationalist Jared Taylor and an array of right-wing conspiracy theories: Texas Gov. Rick Perry is in the thrall of radical Islamists, climate scientists are hoaxing the world about global warming, etc.

Dobbs may have gone quiet on Obama's birth certificate, but he's still comfortable citing the same fringe websites that have fueled the birther story.

The calculation about the first lady's vacations is highly suspect, as well.

Here's what Dobbs said on his show:

DOBBS: The first lady has been on the “spread the wealth” bandwagon for a while. But now, she's taken the message to an odd place, one would think. Before a crowd of supporters wealthy enough to pay up to $10,000 just to see her, the first lady questioned how a well-off family could feel good about themselves while others struggled. The first lady saying, quote, “If a family in this country is struggling, we cannot be satisfied with our own families' good fortune.”

Meanwhile, the first lady has left early for three family vacations, costing taxpayers more than $300,000 extra dollars. Mrs. Obama also went on to ask, quote, “Will we be a country where success is limited to the few at the top? This country is strongest when we're all better off.”

The American Thinker post Dobbs is apparently citing is from December:

Here's the point: Michelle Obama can wear diamond-encrusted undies if she wants, but not on America's dime, and not while advocating for personal sacrifice. Some would say she finances her excessiveness with her own money, but this is only partially true. In essence, she is not.

Here's why: She flew to Hawaii early, at a purported $100K extra in tax monies. Not only that, but lately the first lady is making a habit of premature departures. This is the third time this year she's ventured forth ahead of her husband, bringing the 'Michelle leaves early for vacation' total to over $300,000.

A link on that last phrase leads to a website called White House Dossier. The linked post there says that the military jet flight for Michelle Obama's early trip to Hawaii for the family vacation will cost “more than $60,000, according to government estimates.”

That's it. “Government estimates.” We get nothing more than that as a source.

In the end, the site claims, the “total tab will certainly be in excess of $100,000, and possibly quite a bit more.”

So, it seems that American Thinker's calculation of $300,000 simply multiplies White House Dossier's estimate -- which is itself based on an unsubstantiated estimate -- by three, because Michelle Obama left for vacations early three times in 2011.

Good enough for Lou Dobbs.

As we noted when a similar frenzy kicked up over a Michelle Obama vacation in October, these sorts of estimates are often inaccurate.