By Eugene Robinson - June 22, 2012

WASHINGTON -- In 2006, when George W. Bush was president, federal law enforcement officials came up with a spectacularly dumb idea: Allow powerful firearms purchased in the United States to "walk" across the Mexico border, where authorities would trace the weapons and eventually nab the big-time criminals who supply guns to the ultra-violent Mexican drug cartels.

It is no surprise that most of the weapons promptly disappeared.

But the Bureau of Alcohol, Tobacco, Firearms and Explosives, undeterred by failure, went back to the "gun-walking" technique again the following year -- and used it once more in 2009, after President Obama had taken office, in the tragic fiasco known as Operation Fast and Furious.

These are the facts, and they don't cover any Justice Department officials with glory. But neither do they remotely justify the partisan witch hunt by House Republicans who threaten, without legitimate cause, to hold Attorney General Eric Holder in contempt of Congress. Obama has responded by asserting executive privilege -- effectively shutting down the inquisition.

The House wants to go fishing in a vast sea of documents, some of which relate to ongoing investigations. As a believer in sunshine and disclosure, I don't much care for questionable claims of executive privilege. But I like the politically motivated sideshow the GOP is staging even less.

Holder called the contempt threat "an extraordinary, unprecedented and entirely unnecessary action ... an election-year tactic intended to distract attention."

His frustration -- especially with Rep. Darrell Issa, R-Calif., chairman of the House Oversight and Government Reform Committee -- is understandable. Holder has acknowledged that Fast and Furious was a mistake. He has turned over more than 7,600 documents relating to the botched operation. He has personally testified on Capitol Hill about the matter on nine occasions.

Indeed, Fast and Furious was a grievous error. All told, suspects were allowed to purchase more than 2,000 firearms -- including AK-47s, .50-caliber sniper rifles, powerful handguns -- and fewer than 700 were ever seen again. Of the weapons that were recovered, many were found at crime scenes in Mexico and the United States. But even as it became clear that Fast and Furious guns were being used as instruments of mayhem, the operation continued.

Then in December 2010, U.S. Border Patrol agent Brian Terry was killed in a shootout with suspected illegal immigrants in Arizona. Two assault rifles found at the scene were identified as Fast and Furious weapons; it could not be determined whether one of them fired the bullet that killed Terry.

In testimony before Issa's committee, ATF agent John Dodson, a critic of the operation, stated the obvious: "I cannot begin to think of how the risk of letting guns fall into the hands of known criminals could possibly advance any legitimate law enforcement interest."

Congress has not just the right but the duty to investigate how such a bad idea as gun-walking was conceived and executed over five years -- and to make sure nothing of the sort happens again. The problem is that Issa isn't interested in the truth. He just wants to score political points.

Issa's focus isn't on the operation itself. It's on what Holder and Justice Department officials did or did not say last year when questions were first raised.

What Issa wants to do is manufacture something that can be portrayed as a high-level Obama administration cover-up. The problem is: A cover-up of what? Holder has acknowledged that the operation, of which he says he was unaware, was wrong. He has provided documents showing how wrong the operation was, and why. He has taken responsibility for the whole thing, because he is the boss. As cover-ups go, this is pretty lame.

What should Congress be investigating? The obvious first step is learning how officials in two administrations convinced themselves it was sensible to stand back and watch as powerful weapons passed into the hands of Mexican drug smugglers.

Then Congress should look into the overall flow of firearms from the United States into Mexico. The Fast and Furious weapons were just a small part of a much larger problem. Mexican officials have complained for years that lax U.S. gun laws have the effect of worsening drug-related violence along the border. The damage done by cocaine, marijuana and methamphetamine smuggled north across the border is mirrored by the damage done by guns smuggled south.

If Issa really wants to save U.S. and Mexican lives, he should convene hearings on banning the sale of high-powered weapons. I think Holder would be happy to testify.