The daily horror of mass murder in Mexico hit the U.S. Congress last week in the form of scandal. Sadly, the scandal is not about the incredible loss of life in the drug wars. Instead, Republicans in Congress are busy targeting their least favorite member of the Obama cabinet, Attorney General Eric Holder.

The right has had it in for Holder ever since he managed the controversial pardon of fugitive Marc Rich in the Clinton Justice Department. As attorney general, Holder has angered it further by pushing to have civilian trials instead of military tribunals for alleged terrorists, including Khalid Sheik Mohammed.

Holder has also left the door open to the possible prosecution of CIA agents who implemented coercive interrogations during the Bush Administration. He also upset conservatives in some racially charged cases, refusing to prosecute both ACORN and, in a separate case, two members of the New Black Panthers who were caught on videotape apparently intimidating voters outside a Philadelphia polling station.

Now some in the GOP think they have new ammunition in pursuit of Holder.

Recent congressional testimony indicates that some of the 15,000 drug-related murders in Mexico last year may have been committed with weapons provided to the drug cartels with the help of the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).

The ATF, which is part of the Justice Department, allegedly allowed some 2,000 firearms to be sold to associates of Mexican drug cartels and transported across the border back to Mexico as part of Operation Fast and Furious.

The idea was that ATF would be able to trace the firearms back to their original buyers, enabling them to arrest and prosecute members of the drug cartels. The operation spun wildly out of control and less than half of the firearms have been accounted for. They are still out there, most likely in the hands of drug cartels. Some guns have been recovered and traced to murders and kidnappings in Mexico.

The ATF fiasco has enabled Rep. Darrell Issa, (R-Calif.), chairman of the House Committee on Oversight and Government Reform, to embarrass Holder and call for his resignation.

Behind the scenes, another player in this political game is the National Rifle Association (NRA). They want Holder’s Justice Department to back off any attempt to renew the ban on assault weapons that President Bush let lapse back in 2004.

Wayne LaPierre, the head of the NRA, made his goal plain in a recent speech: “If he didn’t know, then who’s minding the store? … Holder has to go.”

Earlier this week the Wall Street Journal reported that the Obama administration plans to require gun dealers in border states to inform them of multiple purchases of assault weapons. The NRA has already promised that if the plan goes forward it will lead to lawsuits that say it's a violation of Second Amendment rights.

The political games being played around this investigation smell bad. The stench, however, should not be allowed to distract from the very real negligence involved with ATF’s Operation Fast and Furious.

I have been following the Mexican drug war — and believe me, it is a war. People living in Mexico are now more likely to die from violence than people in Afghanistan or Pakistan.

Last year, as part of a joint effort with the U.S. Embassy, the United Nations and the Mexican government, I traveled to Mexico to report on the harrowing effects of the drug war on the Mexican people.

Both governments and the United Nations wanted an American journalist to expose the intimidation of Mexican journalists. The drug dealers shot and killed a newspaper editor from Veracruz, Miguel Angel Lopez, along with his wife and son just last month. He became one of 70 journalists killed in Mexico in the past three years.

After giving public speeches in defense of brave Mexican journalists, I became aware of another chilling aspect of the drug wars — its tragic effect on children. Many of those 15,000 murders last year were of children. Most of the drug gangs favor younger gunmen because they can be easily controlled, paid little to carry drugs or fire guns. For Fox News.com I authored a five-part series on my trips to Mexico called the The Children of Juarez.

It is offensive to think an American government agent would hand out firearms to the drug gangs even if they thought it would help build a case they could prosecute.

ATF Director Kenneth Melson testified to Issa’s committee last week that he did not know the ATF would be unable to track the firearms.

Which is more troubling: that the head of the ATF knew this was going on or that he didn’t know?

Issa and Iowa Sen. Charles Grassley, the ranking Republican on the Senate Judiciary Committee, wrote Holder last week that “knowing what we know so far, we believe it would be inappropriate to make Mr. Melson the fall guy in an attempt to prevent further congressional oversight.”

That’s because they really don’t care about the carnage in Mexico. The real fall guy they have in mind is the attorney general.

Juan Williams is an author and Fox News political analyst. Click here to read his recent five part piece for Fox News Opinion on "The Children of Juarez"This column originally appeared on The Hill.com. His forthcoming book "Muzzled" will be released on July 26.