Demographics offers one answer. Acceptance of gay marriage in the political world is being driven in part by polling that shows overwhelming support for it among young people. By contrast, at least two polls this spring show there is no corresponding generation gap on guns.

People aged 18 to 34 are slightly more supportive of universal background checks than older people and a bit less supportive of limits on the size of ammunition magazines, according to a new Quinnipiac poll. Those aged 18 to 39 are more likely to oppose a ban on assault weapons, a Washington Post/ABC poll found. However, both polls found the younger groups back the general idea of new restrictions on guns and most specific proposals at about the same level as the rest of the country.