Human Rights Campaign (HRC) on Tuesday began organizing a campaign thanking Hillary Clinton, a former first lady, secretary of state and senator from New York, for her endorsement of gay marriage.

In a 6-minute video for HRC's Americans for Marriage Equality campaign released on Monday, Clinton announced that her stance on the issue had changed.

“I support marriage for lesbian and gay couples,” Clinton said. “I support it personally and as a matter of policy and law.”

(Related: Hillary Clinton: I support gay marriage.)

A thank you letter being organized by HRC quickly spread on social media, garnering more than 4,000 Facebook “likes” in its first day.

“Hearing your thoughtful reflection on your experience as Secretary of State and your heartfelt support of marriage equality filled me with pride,” the letter states in part. “Thank you for your dedication to the values that make our country strong and for speaking out on this critical civil rights fight of our time.”

Some pundits have speculated that Clinton's announcement is in preparation for a second bid at the White House in 2016, while others believe she hopes to influence two upcoming Supreme Court cases related to the issue.