A commenter on the attitudes-towards-homosexuality thread writes:

The Pew Research Center did an interesting poll on the subject recently, actually. The number of people who "strongly oppose" gay marriage has sharply declined in the last two years, from 42 percent in February of 2004 to 28 percent in March 2006. The greatest decline is among seniors, Republicans and moderate religious groups. Fully 58 percent of Americans age 65 and older strongly opposed gay marriage in 2004; only 33 percent are strongly opposed now. Seems to support the idea that old dogs can learn new tricks, if people make the case well enough.

Another picks this up:

The Pew study doesn't surprise me. It seems to me that people are more likely to have favorable viewpoints regarding issues associated homosexuality as we as a society talk about it more. Gay marriage or gay parents are no longer little discussed issues shoved in the very far back of the closet. The more those sorts of issues are discussed, the less bizare they sound. It's easy to whip people up into a fervor about something they haven't thought very much about and is never done. It's much harder to freak people out about something when they are informed (regardless of their conclusion) and when they see that other states and countries have done it and the world didn't come screetching to a halt.

To his credit, the first commentator provided a link to the study, and the study paints a rather different picture than the comment suggests. Strong opposition did fall from 42% to 28% between February 2004 and March 2006 -- but only after it had risen from 30% to 42% between July 2003 and February 2004. The change between July 2003 and March 2006 is thus a quite small and statistically insignificant -2%, not -14%. Similar results are present for the subgroups within the sample.

So be careful when reading accounts of surveys. A seemingly striking change may be less "old dogs learn[ing] new tricks" and more the old dogs returning to their old tricks. Perhaps there has been a long-term change in attitudes about same-sex marriage over the years (though then we'd have to ask whether the change stems from individuals' changed views, or people with one set of attitudes dying and being replaced by people with a different set); but the survey that the commenter pointed to didn't really show such a long-term change, and certainly not in the magnitude that the commenter suggested.