A conservative US senator who once opposed gay marriage and made the short list for Republican presidential candidate Mitt Romney's vice presidential pick has changed his stance after learning one of his sons is gay.The reversal makes Ohio Senator Rob Portman the only Republican in his chamber to back gay marriage in the weeks before the US Supreme Court is set to weigh in on the high-profile issue.
Mr Portman discussed his change of heart in interviews with several media outlets. In an editorial published on Friday in The Columbus Dispatch, he said the decision came after much thought.
"I have come to believe that if two people are prepared to make a lifetime commitment to love and care for each other in good times and in bad, the government shouldn't deny them the opportunity to get married," he wrote.
As a member of the House of Representatives in 1996, Mr Portman supported the Defence of Marriage Act, which defines unions as solely between a man and a woman.
Mr Portman said his views on gay marriage began changing in 2011 when his now-21-year-old son, Will, told his parents he was gay and that it wasn't a choice but "part of who he was."
Mr Portman said he and his wife, Jane, were very surprised but also supportive.
He said his son's sexuality forced him to reconsider gay marriage from a different perspective: That of a father who wants all three of his children to have happy lives committed to people they love.
Mr Portman told reporters Thursday that his previous views on marriage were rooted in his Methodist faith.
"Ultimately, for me, it came down to the Bible's
overarching themes of love and compassion and my belief that we are all children of God," he wrote in his opinion piece.
The well-known Ohio conservative, a former White House budget chief, was considered but not chosen last year as Mr Romney's running mate.
Mr Portman said Mr Romney was told of his son's sexuality during the vetting process.
President Barack Obama, a Democrat, has become more outspoken in his support for gay marriage after taking a public stand on the issue during last year's presidential race.
The Supreme Court is expected to hear arguments this month in a challenge to part of the Defence of Marriage Act that denies equal benefits to gay couples.