The Republican National Committee (RNC) unanimously adopted resolutions against marriage equality on Friday, despite rising support for the idea among voters nationwide.

The Washington Post reported that the resolutions, which were approved without debate, include one supporting marriage "as the union of one man and one woman, and as the optimum environment in which to raise healthy children for the future of America."

Another unanimous resolution called for the Supreme Court to "uphold the sanctity of marriage" when it delivers its rulings on cases involving the Defense of Marriage Act and the California law Proposition 8, which also defines marriage as being between a man and a woman.

The resolutions were passed a day after the latest threat from social conservatives to leave the party over the issue. According to The Huffington Post, Family Research Council head Tony Perkins told supporters in a message that they should stop donating to GOP causes unless the party "grew a backbone."

"If you want to invest in the political process, and I encourage you to do so, give directly to candidates who reflect your values and organizations you trust -- like FRC Action," Perkins said in the message.

The Post also reported that Perkins' group joined 12 other organizations in a letter to RNC chairman Reince Priebus threatening to leave the party if it began supporting marriage equality.

In the letter, the groups also said they "deeply resent the insinuation" that they are homophobic, given the existence of groups like GOProud and the Log Cabin Republicans.

A $10 million "autopsy report" released by the RNC on March 18 encouraged Republicans to reach out to LGBT voters emphasizing issues aside from the right to marry.

But an NBC News/Wall Street Journal poll released on Thursday found a slight increase of support for marriage equality, with 53 percent of respondents in favor of it, including 73 percent of Democratic party voters and 54 percent of independents, compared to 34 percent of Republicans. Fifty-six percent of voters also said they supported the issue being settled on a federal level, rather than on a state-by-state basis.

[Image via CNN]

[h/t The Atlantic]