PRRI’s latest research, the 2014 LGBT Issues and Trends Survey, shows support for same-sex marriage jumped 21 percentage points from 2003 – when Massachusetts became the first state to legalize same-sex marriage – to 2013. Currently, a majority (53 percent) of Americans favor allowing gay and lesbian couples to legally marry, compared to 41 percent who oppose. In 2003, less than one-third (32 percent) of Americans supported allowing gays and lesbians to legally marry, compared to nearly 6-in-10 (59 percent) who opposed. PRRI’s Graphic of the Week shows the steady change in support for same-sex marriage since 2003.

The 2013 findings are based on PRRI’s latest survey, which is one of the largest surveys ever conducted on LGBT issues. The ten-year trend tracks nearly 100 polls from PRRI surveys, as well as data from six other major polling sources (ABC/Washington Post, CNN/ORC, Fox News, Gallup, NBC/Wall Street Journal, and Pew Research Center). Notably, none of these major surveys found majority support for same-sex marriage until 2011. With the exception of Fox News, most polls found majority support for same-sex marriage throughout 2013.

That year also brought a wave of states legalizing same-sex marriage. The legalization of same-sex marriage on a state-by-state basis was less linear than the shift in public opinion; Massachusetts was the only state to legalize same-sex marriage from 2003 until 2008, at which point Connecticut became the second state to legalize same-sex marriage. After 2008, legalization of same-sex marriage increased rapidly at the state level. Between 2012 and 2013, the number of states recognizing same-sex marriage doubled again. Today, 17 states plus the District of Columbia recognize same-sex marriage.