Support for same-sex marriage holds steady after 2015 Supreme Court rulingNearly a year ago, the U.S. Supreme Court issued an unprecedented ruling that determined same-sex couples had a constitutional right to marry, a decision that legalized same-sex marriage throughout the country. While the public’s attitudes toward gay marriage remain unchanged from a year ago, they have changed dramatically over the past two decades.

Now, just over half of Americans (55%) say they favor allowing gays and lesbians to marry legally, while 37% remain opposed, according to Pew Research Center’s March poll. A decade ago, the balance of opinion was reversed: 55% were opposed, while 35% were in favor.

(Interactive: See a slideshow illustrating changing attitudes on same-sex marriage.) 

Conservative Republicans remain broadly opposed to same-sex marriageAnd as was the case a year ago, there remains a substantial divide between partisans on the issue. Democrats are more than twice as likely as Republicans to favor gay marriage (70% vs. 33%).

Yet there are key differences within the two parties as well. Among Republicans, 71% of conservative Republicans oppose allowing gays and lesbians to marry legally, more than twice the share of GOP moderates and liberals (34%). A 55% majority of moderate and liberal Republicans favor allowing same-sex marriage.

Within the GOP, these ideological differences also are notable across voters’ primary preferences for the party’s 2016 presidential nominee. About half (52%) of GOP voters who back Donald Trump (now the party’s presumptive nominee) say they oppose same-sex marriage, compared with 70% who preferred Ted Cruz and just 37% who backed John Kasich.

Democrats across the board are supportive of gay marriage (70% favor, 24% oppose), with slight differences by ideology and candidate preference. Liberal Democrats overwhelmingly support gay marriage (84%), compared with a smaller majority of their conservative and moderate counterparts (59% favor). And a wide 83% majority of Bernie Sanders supporters are supportive of gays and lesbians marrying legally (just 15% are opposed), compared with a smaller majority of Hillary Clinton supporters (68%).

Younger, more educated, less religious more likely to support gay marriageViews on gay marriage also vary by age, education and religious affiliation.

The March survey finds a familiar pattern in views of same-sex marriage across age categories: People younger than 30 are most supportive (73%), followed by those who are ages 30 to 49 (61%), those 50 to 64 (47%) and, finally, those 65 and older (38%).

Among those with higher levels of education, there is widespread support. A large majority of the public with at least a college degree (68%) say same-sex marriage should be legal. By contrast, those with a high school degree or less education are split on the issue: While 45% favor same-sex marriage, 46% are opposed.

Views also differ across religious groups, as well as by frequency of religious service attendance. White evangelical Protestants are far more likely to oppose than to favor same-sex marriage (68% vs. 27%). By contrast, most white mainline Protestants (64%) and Catholics (58%) favor gay marriage. Among the religiously unaffiliated, 80% favor same-sex marriage, while just 12% are opposed.

Views of societal acceptance of homosexuality

Changing views among religious groups on whether homosexuality should be acceptedToday, a 63% majority say homosexuality should be accepted by society, a share that also has grown over the past few decades. Fewer (28%) say homosexuality should be discouraged. But there are differences on the issue among religious and partisan groups.

Some religious groups have become more accepting of homosexuality over time while others remain steady. Ten years ago, a 77% majority of those unaffiliated with a religion said homosexuality should be accepted by society, and still today fully 80% say this.

Protestants overall are more likely than they were 10 years ago to say homosexuality should be accepted by society (52% now vs. 38% then). However, Protestant groups continue to have different views of this issue. Among white evangelical Protestants, a third (34%) say homosexuality should be accepted by society, a share that has increased 12 percentage points from 2006. And half of black Protestants now think that homosexuality should be accepted by society, up just slightly from 44% a decade ago.

By contrast, a large majority of white mainline Protestants hold the view that homosexuality should be accepted by society, and this share also has increased over time: Fully three-quarters say this now (76%), compared with 53% in 2006.

Two-thirds of Catholics now say homosexuality should be accepted by society, compared with 22% who say it should be discouraged. Views among Catholics have shifted modestly over the past decade: The share that says homosexuality should be accepted is up 8 points from 2006 (58% said accepted then, 31% discouraged).

Increasing shares in both parties say homosexuality should be acceptedWhen it comes to differences among partisans on whether homosexuality should be accepted by society, there has been a persistent 26-point gap between Republicans and Democrats over the course of a decade.

About three-quarters of Democrats (74%) hold the view that homosexuality should be accepted, up from 59% in 2006. Though slightly fewer independents say the same, they have closely mirrored Democrats on this question over the past decade. Today, two-thirds of independents say homosexuality should be accepted by society, while 25% say it should be discouraged.

Over the past year, declining share of conservative Republicans say homosexuality should be discouragedJust about half of Republicans (48%) now say homosexuality should be accepted, a number that has ticked up 15 points from its low 10 years ago. Republicans today are somewhat more likely than they were a year ago to say homosexuality should be accepted by society. Up until a year ago, a majority of Republicans thought homosexuality should be discouraged by society, but views have since become more mixed. While 41% of Republicans now say homosexuality should be discouraged, 48% think it should be accepted by society.

Conservative Republicans remain more likely to say homosexuality should be discouraged than say it should be accepted, but just about half say this today (49%) compared with 63% in May 2015.

By contrast, seven-in-ten moderate and liberal Republicans now say homosexuality should be accepted (71%), which is little changed since May 2015.

Hannah Fingerhut  is a former research analyst focusing on U.S. politics and policy at Pew Research Center.