On the day that the U.S. Supreme Court was poised to hear oral arguments about same-sex marriage April 28, Hillary Clinton changed her "H" logo to rainbow-colored and tweeted: "Every loving couple & family deserves to be recognized & treated equally under the law across our nation. #LoveMustWin #LoveCantWait."

Clinton came out in support of same-sex marriage in 2013 after more than a decade of opposing it. But her views are particularly in the spotlight now that she is a presidential candidate.

We decided to put Clinton’s statements about same-sex marriage on our Flip-O-Meter, which measures whether a candidate has changed their views without making a value judgment about such flips. We found that as public opinion shifted toward support for same-sex marriage, so did Clinton.

She has had plenty of company among members of her own party to change their stance on same-sex marriage. In 2012, we gave Obama a Full Flop when he announced his support for same-sex marriage.

Currently about three dozen states allow same-sex marriage. The outcome of the decision, expected in June, could mean either that same-sex marriage will become legal in all states or that some states will institute new bans on same-sex marriage. (A spokesman for Clinton’s campaign declined to comment for this Flip-O-Meter item.)

Clinton’s statements during her 2000 Senate race

In 1996, President Bill Clinton signed the Defense of Marriage Act, a law that defined federal marriage as a union between one man and one woman.

Hillary Clinton would face questions about same-sex marriage starting with her 2000 campaign for Senate. Let’s look at the highlights of her statements between 1999 and 2015 in a timeline:

December 1999: Clinton told a group of gay contributors at a fundraiser that she was against the "don't ask, don't tell" military policy signed by her husband.

The New York Times reported that Clinton spokesman Howard Wolfson said she supported the Defense of Marriage Act but added that "same-sex unions should be recognized and that same-sex unions should be entitled to all the rights and privileges that every other American gets."

January 2000: At a news conference in White Plains, Clinton said, "Marriage has got historic, religious and moral content that goes back to the beginning of time, and I think a marriage is as a marriage has always been, between a man and a woman. But I also believe that people in committed gay marriages, as they believe them to be, should be given rights under the law that recognize and respect their relationship."

April 2000: Clinton again expressed support for civil unions. "I have supported the kind of rights and responsibilities that are being extended to gay couples in Vermont," she said.

July 2004: Clinton spoke on the Senate floor against a proposed federal amendment to ban same-sex marriage. (The amendment ultimately failed.) Though she opposed it, she said that she believed that marriage was "a sacred bond between a man and a woman."

However, she said she took "umbrage at anyone who might suggest that those of us who worry about amending the Constitution are less committed to the sanctity of marriage, or to the fundamental bedrock principle that exists between a man and a woman."

October 2006: Clinton told a group of gay elected officials that she would support same-sex marriage in New York if a future governor and Legislature chose to enact such a law.

"I support states making the decision," she said.

As a 2008 presidential candidate

In 2007, all the presidential contenders except for longshot candidates -- both Democrats and GOP -- were against same-sex marriage, the New York Times reported. So were the majority of Americans, polls showed.

May 2007: In a questionnaire for the Human Rights Campaign in 2007, Clinton backed away from the Defense of Marriage Act:

"I support repealing the provision of DOMA that may prohibit the federal government from providing benefits to people in states that recognize same-sex marriage."

In response to a question about whether marriage should be made legally available to two committed adults of the same sex, Clinton marked that she was "opposed" though she stated she supported civil unions.

August 2007: In a Democratic primary debate sponsored by the Human Rights Campaign and LOGO Network (a gay-oriented TV station) Clinton was asked "What is at the heart of your opposition to same-sex marriage?"

Clinton replied: "Well, I prefer to think of it as being very positive about civil unions. You know, it’s a personal position. How we get to full equality is the debate we’re having, and I am absolutely in favor of civil unions with full equality of benefits, rights, and privileges."

As a 2016 presidential candidate

As Clinton got ready for her second presidential bid, she again modified her position.

March 2013: After leaving her position as secretary of state, she announced her support for same-sex marriage in a video with the Human Rights Campaign on March 18, 2013.

"LGBT Americans are our colleagues, our teachers, our soldiers, our friends, our loved ones. And they are full and equal citizens, and they 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, embedded in a broader effort to advance equality and opportunity for LGBT Americans and all Americans."

The comments put her in line with other Democrats at the time who were mentioned as potential 2016 presidential contenders, including Vice President Joe Biden, New York Gov. Andrew Cuomo and Maryland Gov. Martin O'Malley. Obama had announced his support for same-sex marriage in May 2012.

June 2013: Hillary Clinton and Bill Clinton issued a joint statement about the U.S. Supreme Court ruling overturning the Defense of Marriage Act. The congratulatory note didn’t mention that Bill Clinton had signed the law back in 1996: "the Court recognized that discrimination towards any group holds us all back in our efforts to form a more perfect union."

June 2014: NPR’s Terry Gross grilled Clinton about her past positions’ on gay marriage in what led to a testy exchange. Gross tried to get Clinton to explain if she had truly changed her stance or if the shifting political landscape made it possible for her to announce her support.

At one point Gross asked, "Would you say your view evolved since the '90s or that the American public evolved, allowing you to state your real view?"

Clinton replied: "I think I'm an American. (Laughing) And I think we have all evolved, and it's been one of the fastest, most sweeping transformations."

April 2015: On the day of the Supreme Court hearing oral arguments about same-sex marriage bans in a handful of states in April, Clinton changed her "H" logo to rainbow-colored and tweeted a message of support: "Every loving couple & family deserves to be recognized & treated equally under the law across our nation. #LoveMustWin #LoveCantWait."

Our conclusion

Clinton opposed same-sex marriage as a candidate for the Senate, while in office as a senator, and while running for president in 2008. She expressed her support for civil unions starting in 2000 and for the rights’ of states to set their own laws in favor of same-sex marriage in 2006.

As polls showed that a majority of Americans supported same-sex marriage, Clinton’s views changed, too. She announced her support for same-sex marriage in March 2013.

It’s up to voters to decide how they feel about her changed stance, but on same-sex marriage we give Clinton a Full Flop.