Ohio Republican Senator Rob Portman came out in support of gay marriage today. In an op-ed he penned for the Columbus Dispatch, Portman says he opposed marriage equality as a congressman and senator until "something happened that led me to think through my position in a much deeper way."

Portman explains:

Two years ago, my son Will, then a college freshman, told my wife, Jane, and me that he is gay. He said he’d known for some time, and that his sexual orientation wasn’t something he chose; it was simply a part of who he is. Jane and I were proud of him for his honesty and courage. We were surprised to learn he is gay but knew he was still the same person he’d always been. The only difference was that now we had a more complete picture of the son we love. At the time, my position on marriage for same-sex couples was rooted in my faith tradition that marriage is a sacred bond between a man and a woman. Knowing that my son is gay prompted me to consider the issue from another perspective: that of a dad who wants all three of his kids to lead happy, meaningful lives with the people they love, a blessing Jane and I have shared for 26 years.

Portman said his son's revelation caused him to wrestle with his faith, but he ultimately decided that "the Bible’s overarching themes of love and compassion and my belief that we are all children of God" outweighed his belief that the Bible says homosexuality is a sin. Appealing to conservatives, he evokes Ronald Reagan's testament to change beginning at the dinner table, and writes that allowing for same-sex marriage would strengthen, not harm, the institution of marriage:

British Prime Minister David Cameron has said he supports allowing gay couples to marry because he is a conservative, not in spite of it. I feel the same way. We conservatives believe in personal liberty and minimal government interference in people’s lives. We also consider the family unit to be the fundamental building block of society. We should encourage people to make long-term commitments to each other and build families, so as to foster strong, stable communities and promote personal responsibility. One way to look at it is that gay couples’ desire to marry doesn't amount to a threat but rather a tribute to marriage, and a potential source of renewed strength for the institution.

Nonetheless, Portman writes that he believes religious insitutions that oppose homosexuality should be allowed to deny marriage ceremonies to same-sex couples. Read the full op-ed here.