After every mass shooting, partisans retreat to their respective corners on gun control. The National Rifle Association, and the gun owners it represents, are critical forces in our politics, but they may be winning only with Republican voters and in Republican states. Matt Grossmann talks to Mark Joslyn about new research showing gun owners are moving further apart politically from non-gun-owners, with each developing a partisan culture. He also talks to Jay Barth about a new study showing that Obama's elections and NRA influence have accelerated gun policy adoption in the U.S. states, with Republican states deregulation guns and Democratic states regulating them.