The message from the National Rifle Association, fresh off a huge victory over President Barack Obama on gun control, is clear: The fight has just begun. The powerful gun rights lobby gathers in Houston this weekend for its annual convention and organizers anticipate a celebration over the victory in Washington and to recharge for more political struggles as gun control advocates tally their own successes in states around the country. "If you are an NRA member, you deserve to be proud," Wayne LaPierre, the NRA's brash, no-compromises chief executive wrote last week to the organization's 5 million members, telling them...