Gay Marriage Poll 2013: Majority of Americans Support Same Sex Marriage As Support Grows Steadily

As the Supreme Court hears cases arguing over the legality of same-sex marriage, the polls show public sentiment has hit a tipping point. More often than not, Americans now say they support same-sex marriage, a trend that has been continuing for the last 20 years.

The change has been slow and steady, with a plateau in the early years of the millennium, but it has continued unabated for almost a decade and shows no signs of slowing.

Each year, support foe same-sex marriage grows between 1.5 and 2 points nationwide, and opposition diminishes by about the same amount. From 1996 to 2000, support for same-sex marriage grew from about 28 percent to 35 percent.

Support dipped a few points over the next four years, but in 2004 it began to climb again, hitting 51 percent at the beginning of this year. The new surge was perhaps jumpstarted by the 2003 legalization of same-sex marriage in Massachusetts.

Nate Silver at FiveThirtyEight calculates that about half of the annual change in sentiment is due to generational turnover. That is older people, who tend to oppose same-sex marriage, die off and younger people, who tend to support it, come of age.

The other half of the shift seems to come from genuine mind-changing, as people become more acquainted with LGBT people in their lives, same-sex marriage becomes less mysterious and more normal in the media and in society, and people who previously had no stake in the matter begin to follow the zeitgeist. Indeed, support for same-sex marriage surged after President Obama came out in support of it.

Still, it is dangerous to assume that the polls mean same-sex marriage would succeed if put to a vote. Certainly, it was momentous last November when, for the first time, voters approved same-sex marriage in Maine, Maryland and Washington.

But polls generally skew slightly progressive when compared to actual voting results. Many oll respondents don't want to seem uncomfortable or prejudiced, so they say they support same-sex marriage when they don't. And many younger people who support it don't vote, whereas older people are the most reliable voting bloc.

So change is coming, but it may be several years before the country is ready for a nationwide referendum, whatever happens at the Supreme Court.