President Obama’s recent expression of support for same-sex marriage has highlighted long-term changes in opinion on the issue. In interviews with more than 5,000 adults conducted in 2011-2012, prior to Obama’s announcement, 46% favored gay marriage while 44% were opposed. (See detailed tables for a breakdown among subgroups by year).

Four years ago, a majority of Americans (53%) opposed gay marriage, while 38% favored it, based on combined surveys from 2007-2008. And in the previous presidential campaign (2003-2004), just 32% supported gay marriage while 59% were opposed.

Combining data from a number of surveys makes it possible to track changes in opinions among smaller groups in the population – including younger and older people across racial, ethnic, partisan and religious groups. The analysis finds continued age differences in support for gay marriage among blacks and Hispanics, as well as Republicans, Democrats and independents. But since 2003-2004, support for gay marriage has increased among most groups, among young and old alike.

Click here to view these detailed tables on gay marriage attitudes.