The National Rifle Association has crossed that line.
In an ad released Tuesday, the NRA calls Obama an "elitist hypocrite" because his children have armed guards protecting them while children of ordinary citizens don't.
According to , an Obama spokesman fired back at the NRA about the ad.
"Most Americans agree that a president's children should not be used as pawns in a political fight," Jay Carney said Wednesday.
"But to go so far as to make the safety of the president's children the subject of an attack ad is repugnant and cowardly."
The president of the NRA rebutted with an interview with the National Review.
"We didn't name the president's daughters," David Keene said, according to .
"We didn't criticize them. What we said is that these are people who think that their families deserve protection that yours don't."
The controversial ad comes amid a battle for public opinion between the NRA and the White House about gun control, sparked from the public outcry from the Newtown elementary school shooting last month. On Wednesday, according to , the President proposed a new assault weapons ban and mandatory background checks for all gun buyers.
The NRA has also produced a with a similar message and posted it on their website.