In revealing his support for same-sex marriage last week, President Obama attributed his change in thinking to a series of key conversations and experiences.
Talking to members of his staff and gay service members in committed relationships made it more difficult to justify why they should not have the right to marry, he said.
Just as influential in his thinking, according to Obama, were dinnertime conversations with his 13- and 10-year-old daughters, who have friends with two mothers or two fathers.
"It wouldn't dawn on them that somehow their friends' parents would be treated differently," he said. "It doesn't make sense to them and, frankly, that's the kind of thing that prompts a change in perspective."
While separating the personal from the political is impossible in the president's case, others who have moved in the same direction on the issue say they immediately recognized themselves in Obama's remarks. Once comfortably opposed, they found their views shifting as a result of sometimes uncomfortable dialogues taking place at churches, workplaces, soccer fields and statehouses.
"I had the same conversation with my daughter," New York Assemblywoman Sandra Galef, a Democrat representing Westchester County. "My daughter told me, 'Mom, you're old-fashioned. What difference does it make if people love each other? Everyone should have their rights.' She really just totally disagreed with her mom."
Galef, 72, credits those talks with moving her from voting in 2009 against a bill that would have legalized same-sex unions in the state to voting for a similar bill two years later.
"My daughter, I think, really opened my eyes to the fact that I grew up in a different age and just made it so clear that I wasn't thinking like a more modern person on this topic," she said.
Before Obama became the first sitting president to endorse marriage rights for same-sex couples, other politicians had attributed changes of heart on the issue to having gay people leading comfortably conventional lives in their worlds.
The leader of the Iowa Senate, Mike Gronstal, held back a constitutional amendment that would have banned gay marriage in his state in 2009 after his daughter changed his mind on the subject. Former Vice President Dick Cheney and San Diego Mayor Jerry Saunders also came out for same-sex marriage after learning their daughters were lesbians.
A 2011 poll by the Washington, D.C.-based Public Religion Research Institute found that support for gay marriage is twice as high among people who have a close friend or family member who is gay. While 47 percent of Americans favor gay marriage, according to the poll, that number rises to 64 percent among people with intimate ties to gays and lesbians.
But knowing, admiring and even loving someone who is gay is not a foolproof prescription for embracing same-sex marriage.
Robert Tyler, a California lawyer who has helped defend the state's one man-one woman laws on marriage, considers some of the opposing gay lawyers to be friends. He respects them as lawyers, as spouses and as parents. But that respect has not translated into his thinking they should be able to get married.
"I'd take the coat off my back and give it to them if they needed my coat," he said. "Yet at the same time, that doesn't cause me to change my position on the public policy arguments just because I feel that way."