As the Supreme Court prepares to hear arguments on same-sex marriage, a new poll shows that more American adults are believed to be in gay marriages or domestic partnerships than had been previously thought.
A Gallup poll released on Friday found that nearly 2 million adults are part of a same-sex couple, of whom about 780,000 are married. Those results are higher than findings by the Census Bureau and by the Centers for Disease Control and Prevention.
The increase is a reflection of the growth in the number of states that have legalized same-sex marriage in recent years.
Just 13 states have completely barred same-sex marriage as many courts have struck down state barriers to gay marriage and to the recognition of other issues related to marriage such as adoption and end-of-life issues.
The latest relationship numbers come amid polls showing a general acceptance of same-sex marriage in recent years. A Washington Post-ABC poll released this week found that 61% of Americans said they support allowing gays to marry and 35% said they were opposed. A decade ago, opponents outnumbered supporters of gay marriage by 58% to 39%.
The Supreme Court will hear oral arguments on Tuesday on a set of cases that challenge state bans on same-sex marriage in Kentucky, Michigan, Ohio and Tennessee.
The hearing comes two years after the nation's top court ruled unconstitutional the federal Defense of Marriage Act that prohibited the federal government from recognizing the marriages of same-sex couples.
The ruling in the Defense of Marriage case did not legalize same-sex marriage, but did set off a flurry of state and local suits, which led to same-sex marriage being legalized in 37 states and the District of Columbia.
According to the latest Gallup poll, about 0.3% of adults in the United States are married to a same-sex spouse and an additional 0.5% identify as being in a same-sex domestic partnership.
That works out to about 390,000 same-sex married couples in the United States and about 600,000 domestic partnership couples -- for a total of 990,000 couples, or about 2 million adults.
Gallup's estimate is larger than the U.S. Census Bureau's American Community Survey, which in 2013 put the total number of same-sex couples at roughly 727,000. Of this group, more than 250,000 reported they were married.
Separately, analyses by the CDC in the 2013 National Health Interview Survey put the number of same-sex couples at 690,000, of whom about 130,000 were married by the end of the year.
All such findings are subject to error since people sometimes hide or embellish the truth. There can be other factors, such as different methodology, as well.
Still, all three findings agree that the number of gay marriages and partnerships have been rising in recent years.
The Gallup results are based on 80,568 interviews conducted on Gallup Daily tracking from Jan. 28-April 19. The margin of sampling error is plus or minus one percentage point.