Perhaps. just perhaps, those Senators didn't vote for the gun control bills because despite their high and noble sounding titles, the actual laws proposed were absolute crap.
This is something I have emphasized in conversations. A false dichotomy has been created that if you don't support every bill that is proposed you are in favor of shooting up elementary schools. This was a really bad bill. I saw very little publicized about what was in the actual bill; I doubt that was an oversight.
I remember when Representative Giffords was shot, there were numerous testimonials of how she reached across the aisle, listened to, and respected other people's opinions. It seems to me that either those testimonies were false or she has abandoned her previous virtues in that regard.