As its convention opened today in Houston, the National Rifle Association was celebrating the defeat of background checks in the Senate. But gun control advocates say it's not over yet. Today's Houston Chronicle published an op-ed piece by former astronaut Mark Kelly, whose wife, Gabby Giffords was shot in the head while she was a member of Congress. He accused the NRA's chief executive, Wayne LaPierre, of exploiting people's fears for gun-industry profits. Julie Bykowicz, national political reporter for Bloomberg News, is in Houston for the NRA convention.