Some of the party’s biggest financiers, attempting to transform the GOP’s approach, have been helping to bankroll the American Unity Fund, a group that has launched a well-organized, behind-the-scenes effort to lobby convention delegates who will draw up the platform. It is asking them to adopt language that would accommodate same sex marriage.

The organization, which has offices in Washington, D.C., and a growing army of volunteers spread out across the country, has the backing of billionaire investors Paul Singer, Dan Loeb, Seth Klarman and Cliff Asness, who have been outspoken in calling for the GOP to moderate its rigid stance on social issues.

American Unity Fund’s efforts are the most assertive yet to alter the party’s posture on gay marriage. During the Republican National Committee’s winter meeting in January, staffers with the group huddled with influential party officials over drinks at the posh Belmond hotel in Charleston, South Carolina. The organization is also planning to have a presence at the committee’s spring meeting this month in Hollywood Beach, Florida. Over the past week, the group has reached out to a number of RNC members by phone.