Her position has evolved, she says, from personal experience, her experience as the nation's top diplomat and her love of the law. She focuses on the national and global progress of gay rights more than on her own personal change.
The former Cabinet member does not say when she came to support gay marriage but suggests that she did not feel able to speak freely until she left her post at the beginning of February. "Now, having left public office, I want to share some of what I learned," she says. In a blog post presenting Clinton's testimonial, HRC President Chad Griffin writes that since she has now left office, Clinton "can speak publicly about the issue that is so important to all of us."
Clinton's declaration is not much of a surprise -- her husband and daughter are both public supporters of gay marriage. She begins the video by recalling that she declared in Geneva over a year ago that “gay rights are human rights, and human rights are gay rights" and discussed the issue in "some pretty tough conversations with foreign leaders." She also notes that she changed State Department policy "to ensure that our LGBT families are treated more fairly." That work, she says, "inspired and challenged me to think anew about who we are and the values we represent to the world."
But the announcement comes after years of speculation and is a significant shift. The news is especially relevant given the possibility that Clinton might run for president in 2016, when gay rights will likely be a major issue in the Democratic primary.
Here a look at other leading political figures on the issue: