In the NY Times, Ross Douthat links to some Gallup data showing a decline in support for gun control since 1990, and offers an interesting argument about the reason. He suggests that it's one aspect of a general move towards individualism--the idea that people should be allowed do what they want as long as it doesn't directly hurt other people. With many issues, this idea has "liberal" implications (same-sex marriage, legalization of marijuana) but with gun control it has "conservative" implications. Before his column came out, I found another series of questions on gun control, "do you favor or oppose stricter gun control laws?" (There were minor variations in question wording, but they seem unlikely to have made a difference). Here is the plot of percent favor minus percent opposed:
There is also some downward trend, but also a lot of short-term change (maybe in response to events in the news). I think this volatility counts against the idea that the decline reflects a general change in values. That kind of change is driven mainly by generational replacement, producing a gradual and steady change (which is what you see with same-sex marriage). Also, as Douthat notes, the decline in support for gun control 1990 might also be explained as a response to declining crime rates. If support for gun control declined in the 1970s and 1980s, when crime was steady or increasing, that would be stronger evidence that it was related to a rise of individualism. Gallup also asked a question about handguns that goes back farther, and my impression is that opinion didn't start to show a trend until about 1990. I may take a closer look in a future post.