If you're in the bayous of Louisiana, or the plains of Montana, a gun can be your defense against predators. When the police are far away, you may feel strongly about needing a gun for self-defense. And if someone says we should restrict guns, you worry.
But in urban areas like Philadelphia or South Central Los Angeles or even my home town in Indiana, guns may be best known for injuring young people as a result of gang violence, or police officers at a traffic stop or domestic quarrel. But when you say "we need to controls the weapons available on the streets," other Americans misinterpret you as wanting to limit their rights.
Paul, it might come as a shock to you that people in 'urban areas' also might 'feel strongly about needing a gun for self-defense' against that gang-violence or violent domestic. You want to lump them in the same category as the criminals and insane. You want to pass laws that effect not only 'city people', but everyone else as well.
Howabout we try and control the criminals that are on the streets?