PHILADELPHIA — No issue has elicited greater cheers from inside the convention hall this week than gay rights.
But it hasn't always been that way.
The party only officially embraced same-sex marriage in its platform four years ago, and this year's nominees, Hillary Clinton and Tim Kaine, came around on the issue after that.
This year, though, speaker after speaker at the Democratic National Convention demanded equal treatment based on sexual orientation and gender identity. Rep. Sean Patrick Maloney, a New York congressman who has led the fight on Capitol Hill, spoke Thursday. And for the first time at any political convention, an openly transgender woman addressed the delegates.
The Democratic party has evolved in "an incredibly short period of time," said New Hampshire Democratic Party chairman Raymond Buckley, the first openly gay vice chair of the Democratic National Committee.
"It was hard," he said of the push to include marriage equality in the platform four years ago. "Allowing people to get there is always the answer."
Speakers on the final night of the convention, including Human Rights Campaign President Chad Griffin, underscored that the Democratic Party is the original home of the lesbian, gay, bisexual and transgender community.
"Long before Donald Trump struggled to read the letters 'LGBTQ' off a teleprompter last week, Hillary Clinton stood before the United Nations and boldly declared that gay rights are human rights and human rights are gay rights," Griffin said.
A night earlier, the Democratic delegates erupted with applause during a video introduction for Vice President Joseph R. Biden Jr. that replayed his 2012 "Meet the Press" interview in which he came out in support of gay marriage.
What was left to history, though, was the reminder that it was Biden who pushed the president forward on the issue, just four years ago, when the Democratic Party was less hospitable to the LGBT community than it is now.
The first openly transgender convention speaker, Sarah McBride, testified to that evolution in her own Thursday night convention speech.
"Four years ago, I came out as transgender while serving as student body president in college. At the time, I was scared. I worried that my dreams and my identity were mutually exclusive," she said.
But times have changed, said McBride, who serves as national press secretary for the Human Rights Campaign.
And nowhere is that more visible than in the political evolution of this year's Democratic ticket.
Vice presidential nominee Tim Kaine, whom the Clinton campaign is touting as a "progressive" addition to the ballot, said he opposed same-sex marriage in a 2005 campaign ad during his successful run for Virginia governor. His position shifted — first toward support of civil unions and then for same-sex marriage — by the time he ran for the Senate in 2012.
Clinton has also had to answer for her husband's legacy on the issue. President Bill Clinton signed both the Defense of Marriage Act, which defined marriage for federal purposes as one between a man and a woman, and the "Don't Ask, Don't Tell" compromise legislation — which allowed gay men and women to serve in the military only if they didn't tell anyone about their sexual orientation.
Obama repealed the stopgap policy in 2011 after nearly two decades on the books. This year, he appointed an openly gay man to serve as secretary of the Army.
Hillary Clinton announced her support for same-sex marriage in a March 2013 video . But in 2014, the issue was the focus of a tense interview with public radio's Terry Gross in which Clinton discussed her changing views.
"I think I'm an American," Clinton said. "And I think we have all evolved, and it's been one of the fastest, most sweeping transformations."
The following year, the Supreme Court made same-sex marriage the law of the land.
Ed Greenleaf, a Clinton delegate from South Carolina and former Republican, said he doesn't fault Clinton for not embracing same-sex marriage right away.
"Neither did I. As a gay man in SC, I learned you sometimes have to go along to get along," he said. He acknowledges that this progressive platform, calling for lifting rules that block federal funding for abotion, may still be politically risky in South Carolina. "You know what, I don't care."
Wisconsin Sen. Tammy Baldwin, who is gay, pointed to the greater visibility of LGBTQ families for helping change the party's position over last several years.
"Also, we listen to our millennials, and they can't see the world any other way," she said.
Earlier this week she attended the LGBTQ caucus meeting at the DNC, and it was standing room only. In earlier years, it was never like that. "It made my heart swell," she said.
More than 60 percent of Americans now support the idea, according to a July Gallup Poll . In 1996, only 27 percent said same-sex marriage should be legal.
Support for gay rights has also become increasingly bipartisan, with prominent Republicans such as Ohio Sen. Rob Portman embracing it.
And after last month's shooting at a gay nightclub in Orlando, Florida, a few Republicans have spoken about gay rights in the context of national security.
"As your President, I will do everything in my power to protect our LGBTQ citizens from the violence and oppression of a hateful foreign ideology, believe me," Donald Trump told the crowd at last week's Republican National Convention in Cleveland.
And then the Manhattan billionaire went off script, adding, "And I have to say as a Republican, it is so nice to hear you cheering for what I just said. Thank you."
Another GOP convention speaker , venture capitalist Peter Thiel, told the Cleveland crowd last week, "I am proud to be gay. I am proud to be a Republican. But most of all I am proud to be an American."
Still, the GOP's platform continues to define marriage as between one man and one woman and condemns the Supreme Court's recents rulings in favor of marriage equality. Beyond the marriage issues, many conservative Republicans are concerned about allowing transgender people to use bathrooms of their choice. A law in North Carolina, forcing people to use the bathroom assigned to the gender of their birth, has inflamed passions on the issue.
Asked at the Republican convention whether she feared that position would turn off LGBT voters, North Carolina Republican and RNC Rules Committee member Virginia Foxx said, "We are not."