Hillary Clinton has officially endorsed same-sex marriage in a video released on YouTube on Monday by the Human Rights Campaign, a leading American gay rights organization.

"LGBT Americans are our colleagues, our teachers, our soldiers, our friends, our loved ones," Clinton said. "And they are full and equal citizens and deserve the rights of citizenship. That includes marriage. That's why I support marriage for lesbian and gay couples."

"I support it personally and as a matter of policy and law," she continued, "embedded in a broader effort to advance equality and opportunity for LGBT Americans and all Americans."

Clinton spoke for nearly six minutes, looking directly into camera, in a video without cuts, camera movement or music. She began by discussing her role as an ambassador for American values while she served as Secretary of State -- values she says include equality and dignity for all people. She detailed the way people she met who lived in oppressive regimes looked up to the United States as a place where the LGBT community could thrive without fear.

After proclaiming her unequivocal support for same-sex marriage, Clinton spoke of the joy she felt when he daughter Chelsea was married several years ago.

"To deny that opportunity to any of our daughters and sons, solely on the basis of who they are and who they love, is to deny them the chance to live up to their own God-given potential," Clinton said.

The White House released a statement offering its support for Clinton's stance and reiterating President Obama's agreement. During last year's presidential election, the Obama campaign's official platform included support for same-sex marriage, a first for either a sitting president or a major party presidential contender.

Clinton's stance is no surprise, as her husband, former President Bill Clinton, also recently stated his support for same-sex marriage, as well as for the repeal of DoMA, the Defense of Marriage Act he signed into law during his presidency, which prohibits the federal government from recognizing same-sex marriages even in states that have made them legal.

And, of course, today's announcement fuels speculation that Clinton is laying the foundation for a 2016 presidential run. If she does enter the race, she will be the top contender for the Democratic nomination, and the favorite to win the election.

It seems unlikely that a Republican presidential nominee will be able to publicly support same-sex marriage in only three years, making the LGBT community yet another demographic the Republicans an count on supporting their opponent. In 2012, gays and lesbians accounted for between 5 and 7 percent of the vote in many important states.

While individual Republicans support same-sex marriage -- like Rob Portman of Ohio and former Vice President Dick Cheney, both of whom have a gay or lesbian child -- the base continues to be resistant to the idea. But for most Americans under the age of 40, the issue is decided. Even without Republican support, the tide has shifted. It is a question of when same-sex marriage becomes legal across the country, not if.