The Republican National Committee has reaffirmed its opposition to gay marriage with a slate of resolutions passed unanimously at its spring meeting.

Several resolutions re-establishing the party's official position were adopted without discussion on Friday.

One resolution states the party's belief that "the institution of marriage is the solid foundation upon which our society is built and in which children thrive; it is based on the relationship that only a man and a woman can form."

The RNC also expresses its “support for 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.”

And one clause addresses the gay marriage cases currently under consideration by the Supreme Court, one concerning California's ban on gay marriage and the other concerning the federal act that defines marriage as being between a man and a woman.

"The Republican National Committee implores the U.S. Supreme Court to uphold the sanctity of marriage in its rulings on California’s Proposition 8 and the Federal Defense of Marriage Act," the clause reads.

At the same time, polls show public support for gay marriage is at an all-time high, and a wave of lawmakers have voiced public support for legalization in recent months. 

All but three Democrats in the Senate have expressed their support for gay marriage, and two Republican senators — Rob PortmanRobert (Rob) Jones PortmanCommittee chairman aims for House vote on opioid bills by Memorial Day Flake to try to force vote on DACA stopgap plan Congress punts fight over Dreamers to March MORE (Ohio) and Mark KirkMark Steven KirkHigh stakes as Trump heads to Hill Five things to watch for at Trump-Senate GOP meeting Giffords, Scalise highlight party differences on guns MORE (Ill.) — have shifted their views and spoken in favor of it.

But the social conservative base of the GOP has pushed back against the emerging trend. A coalition of 13 social conservative groups sent RNC Chairman Reince Priebus a letter on Thursday demanding the committee reaffirm the 2012 party platform.

“We respectfully warn GOP Leadership that an abandonment of its principles will necessarily result in the abandonment of our constituents to their support," the conservatives wrote.

One of the resolutions passed Friday explicitly reaffirmed a number of the planks of the party's 2012 platform that dealt with social issues, including opposition to abortion rights and gay marriage.

The RNC has also been under pressure from the Family Research Council. Tony Perkins, the group's president, on Thursday criticized the RNC over a report released last month that suggested the party should reconsider its messaging on same-sex marriage to appeal to younger voters.

"Until the RNC and the other national Republican organizations grow a backbone and start defending core principles, don’t send them a dime of your hard-earned money," Perkins said in the email, a copy of which was obtained by CNN. 

— Justin Sink contributed to this report.