Poll: 2 million Americans in same-sex relationships

Nearly 2 million Americans are part of a same-sex couple, including 780,000 who are married — much higher than previously thought, according to a new poll.

Days before the Supreme Court will hear arguments over a challenge to same-sex marriage bans in states, a new Gallup poll shows the number of same-sex couples in the United States is growing rapidly in just the last few years.

{mosads}Gallup reported Friday that roughly 0.3 percent of all adults in the U.S. are married to a same-sex spouse, and all told, 0.5 percent say they are in a same-sex relationship. In total, Gallup estimates there are 990,000 same-sex couples across the nation.

Those figures are significantly higher than other attempts to quantify the number of same-sex relationships in the nation. In 2013, the Census Bureau reported that 727,000 same-sex couples in America, with just 250,000 reporting themselves as married. And a 2013 survey by the Centers for Disease Control and Prevention estimated only 690,000 same-sex couples and only 130,000 marriages.

The rapid increase comes as states have increasingly cleared the way for same-sex marriages in their states, either via the legislature or through court rulings. Just 13 states explicitly ban same-sex marriages at this point.

The case pending before the Supreme Court could require the justices to weigh in on whether there is a constitutional right to marry, and whether same-sex marriages must be recognized across state borders.