This was mentioned in GMN, but I didn't think new lows were a possibility for the NRA. I was wrong:

David Frum:

Even if [armed guards in schools] were a good idea, the NRA's sneering references to the president's family are beyond the pale. As the makers of the NRA ad should know, and probably do know, the First Family has come under years of racially coded attack for their "uppityism," as Rush Limbaugh phrased it. This latest attack ad looks to many like only one more attempt to enflame an ancient American wound. Generally speaking, a president's family should not be subject to political criticism. That rule was honorably upheld in the case of the Bush daughters, who grew into fine young people, and the rule should be same for the Obama daughters—especially if it's true, as has been widely reported, that this first family has faced a unique degree of threat.