California Attorney General Kamala Harris and New York Attorney General Eric Schneiderman have endorsed an effort to add marriage equality to the 2012 Democratic Party Platform.

Gay glossy The Advocate reported that Harris is among the seven Obama for America co-chairs to endorse the effort. The site also quoted Representatives Jan Schakowsky of Illinois and Charles Gonzalez of Texas as being in favor of the inclusion.

The Huffington Post on Thursday published a letter from Schneiderman calling on members of the Democratic Party Platform Drafting Committee to add marriage equality to the platform.

“Because the Democratic Party has a noble history of fighting for the human and civil rights of all Americans, it is time to hold true to this record and add to the Party's legacy by supporting the freedom to marry for all couples,” Schneiderman wrote.

New Hampshire Senator Jeanne Shaheen and former Wisconsin Senator Russ Feingold also endorsed the plank earlier this week.

Last month, Freedom to Marry launched the Democrats: Say I Do campaign, which calls on the Democratic National Committee (DNC) to endorse marriage equality in this year's platform. The DNC will ratify the document during its national convention, which begins September 3 in Charlotte, North Carolina.

“This outpouring of support from elected officials and trusted Democratic advisers is phenomenal,” Marc Solomon, national campaign director for Freedom to Marry, said in a statement. “At its best, the Democratic Party stands strongly for freedom and equality for every American. Over the coming weeks and months, we will build and grow this campaign and make the case to Democrats throughout the country that a freedom to marry plank is just, politically smart, and what Democratic voters expect of their Party.”

Outgoing Human Rights Campaign (HRC) President Joe Solmonese is also a co-chair of the president's re-election campaign.

(Related: Nancy Pelosi supports effort to endorse gay marriage in Democratic platform.)