Support for same-sex marriage in the United States is declining, especially among Republican voters, according to new data.

Gay marriage was legalized nationwide in 2015, after the landmark Supreme Court case Obergefell v. Hodges. While approval for same-sex marriage steadily increased across political affiliations, data from Gallup has shown a decrease over the past two years.

The majority of Americans still approve of it, with 69% saying same-sex marriages should be legal. The peak for national approval of gay marriage was 71%, in 2022. Slightly fewer Americans believe that gay marriage is "morally acceptable," with 64% agreeing with the statement in 2024, suggesting that some Americans want same-sex marriage to be legal without personally liking the idea.

Democrats remain largely supportive of same-sex marriage, though their approval has slightly decreased. The Gallup poll shows that 83% of Democrats support same-sex marriage, which is a minor drop from highs of 87% in 2022.