On Tuesday’s Andrea Mitchell Reports on MSNBC, Mitchell hosted two liberal guests in a discussion about President Obama’s national service program and the prospects for more gun control laws being passed by Congress in the near future. Speaking to New York City Mayor Michael Bloomberg, Mitchell repeated a grossly inaccurate statistic that 90 percent of guns used by Mexican drug cartels are manufactured in the U.S. Mitchell: "Mr. Mayor, first to you, why not go after the assault weapon ban, as President Calderone in Mexico is calling for? Ninety percent of the weapons used in the drug cartel crimes south of the border are said to have originated in the United States."

But, as previously documented by Mike Sargent, FNC's William LaJeunesse reported on April 2 that 83 percent of guns recovered from Mexican drug cartels are not from the United States. Most of these weapons are never submitted to the U.S. for tracing because they are clearly not American in origin.

After Bloomberg advocated passage of an assault weapon ban, but later indicated that almost all those killed using guns each day are killed using "illegal handguns," Mitchell did not take the opportunity to challenge the Mayor on just how much impact an assault weapon ban could have if such guns are are so rarely the weapon of choice by criminals. She then moved on to set up New York’s Democratic Congresswoman Carolyn McCarthy to promote the passage of more gun laws. Mitchell: "And, Mr. Mayor, you mentioned Virginia Tech, Columbine anniversary was yesterday. Only weeks ago, we had the killings of police officers in Pittsburgh and in Oakland. Congresswoman McCarthy, is there any chance that something will be done in Congress? And also the gun show loophole which is sitting out there?"

On Sunday's CBS Evening News, without providing a pro-gun rights view for balance, correspondent Randall Pinkston filed a report which featured the views of two public figures who support an assault weapons ban, including a clip of Congresswoman Carolyn McCarthy, a New York Democrat and leading supporter of gun control in Congress, as she complained about her efforts being thwarted by the NRA.

RANDALL PINKSTON: She ran for Congress, intent on curbing access to guns, but hasn't had much success.

REP. CAROLYN MCCARTHY (D-NY) CLIP #1: People say, "Yes, we should have better laws. Yes, we shouldn't have assault weapons." But then it goes away.

MCCARTHY CLIP #2: All they hear from is the NRA.