Support for marriage equality has hit a new high in the United States.

According to a Gallup survey released this week, two in three Americans (67%) support marriage rights for gay and lesbian couples, up 40 percentage points since 1996, the year Gallup first polled on the question.

Gallup conducted its annual Values and Morals poll May 1-10. Pollsters interviewed 1,024 adults living in all 50 states and the District of Columbia.

According to Gallup, more than 10.4% of LGBT adults are involved in a marriage with a same-sex spouse.

“Some of the increase in support may be due to greater numbers of lesbian, gay, bisexual and transgender (LGBT) adults getting married in the U.S.,” Gallup wrote in reporting its findings.

In its landmark 2015 Obergefell decision, the Supreme Court found that gay and lesbian couples have a constitutional right to marry, striking down state constitutional amendments and laws that defined marriage as a heterosexual union.

(Related: NOM's Brian Brown: Gay marriage bans may soon “come back to life.”)

While support for same-sex marriage has increased among Democrats (83%) and independents (71%), less than half of Republicans (44%) favor marriage equality, down 3 percentage points since last year's survey.

“Reaching a national consensus on the issue would depend more on greater acceptance among Republicans, who remain mostly opposed to legally recognized same-sex marriages,” Gallup wrote.