One certainty in the weeks to come is that both parties in Washington will carefully watch public opinion on gun control and the Second Amendment, and whether any impact lasts. Opposition to stricter laws has proved resilient. Firearms are in one-third or more of households and suspicion runs deep of an overbearing government whenever it proposes expanding federal authority. The argument of gun-rights advocates that firearm ownership is a bedrock freedom as well as a necessary option for self-defense has proved persuasive enough to dampen political enthusiasm for substantial change. In July, a gunman opened fire on Aurora, Colo., theatergoers watching the Batman movie, "The Dark Knight Rises," killing 12 people. The next month, an Associated Press-National Constitution Center poll found that 49 percent of Americans felt laws limiting gun ownership infringe on the right to bear arms, while only 43 percent said such laws do not infringe on those rights. By many measures, Americans have changed on the question since the 1990s, when people favored gun control over gun rights -- by a 2-to-1 margin in polling after the 1999 Columbine High School massacre in Colorado. In a Gallup poll last year, 55% said gun laws should stay the same or be more lenient, while 43% wanted them toughened. None of this is lost on Washington, where most Democrats long ago abandoned their advocacy of gun control, convinced that it is a losing issue for them. Obama has proposed reinstituting a federal ban on military-style assault weapons that lapsed years ago, but he's put no weight behind it, while signing laws letting people carry concealed weapons in national parks and in checked bags on Amtrak trains. After the movie-theater attack, Obama declared "we should leave no stone unturned" to keep young people safe in a speech indicating he would challenge Congress to act on gun control. That expectation lasted for one day. The White House swiftly clarified that Obama would not propose stiffer gun laws this election year and favored more effective enforcement of existing law -- a position hardly distinguishable from that of his Republican rival, Mitt Romney.