Richard Socarides frames his story about Republican Ohio Senator Rob Portman’s shift on same-sex marriage in terms of the senator’s "brave, gay son." It's fine to praise Will Portman for coming out to his father when he was 19, but I think it's more correct to congratulate him for fulfilling his obligation to do so.

My uncle, Francis Schwarze, also came out to his parents when he was 19, in -- this is still astounding to me -- 1963. He was a freshman at the University of Southern California, still living at home. He wasn’t caught, but came out of his own volition. As my mother put it to me, "He had become involved with someone and needed space to be gay."

This wasn't easy for the son of an electrician growing up in the suburbs in the early 1960s. My ashamed grandfather stopped paying Frankie’s college tuition, and Frankie dropped out of USC. In the late 1970s, Frankie died from brain cancer, and his parents interfered with his friends' contact with him during his long treatment.

I never met Frankie, but his precedent eased my own coming out as a teenager in two ways. One was that I knew if Frankie could handle coming out of the closet in 1963, I ought to be able to do it in 2000. The other was that my parents had watched my grandparents' mistreatment of Frankie up close and with horror and would never allow themselves to repeat it.

This is why coming out is a duty: Every time a gay or lesbian person demands acceptance, they make it easier for others to do the same. We have the power to change people's political and personal attitudes toward gays simply by being present and known to be gay; we can only exercise that power if we come out.

San Francisco Supervisor Harvey Milk got this right in 1978, when he admonished his fellow gays and lesbians to come out of the closet in order to build opposition to a ballot measure that would have banned gays and lesbians from teaching in public schools: "Come out to your relatives. I know that is hard and will upset them but think how they will upset you in the voting booth."

This obligation is only stronger now that social acceptance of gays and lesbians is higher, meaning the cost of coming out has declined. And it lies particularly with those in positions of privilege and power, who have the resources to withstand negative reactions. Coming out was stressful for me like it is for most people, but let’s be real: Announcing that you’re gay in a wealthy family in a progressive suburb of Boston as you’re about to enter Harvard University is a pretty easy hand to play. I could hardly claim a hardship that would justify staying in the closet, especially with Frankie’s example before me.

Coming out may have been more daunting for Will Portman because his father was a Republican officeholder with an anti-gay voting record; or maybe he had good reasons to expect his dad to react in exactly the way he did. But while his father’s position may have made coming out harder, it also made it all the more obligatory, because of the possibility it would lead to the outcome that we saw last week. He was given an unusual opportunity to use his coming out to materially change the prospects for gay rights and gay acceptance in America, and he took it.

And that will make it easier for teenagers not operating from a position of privilege to be themselves without hiding. There are a lot of teenagers for whom, unlike Will Portman or me, coming out entails risk of familial rejection, homelessness and violence. There is a reason organizations such as the Ali Forney Center, which provides housing and support to homeless LGBT youth in New York City, need to exist. Making public policy less anti-gay will help these youth but arguably more importantly, demands for social acceptance of gays and lesbians at the elite level trickle down into mass attitudes and make it less likely that families will reject their gay children in the first place.

At least half the members of the Senate still oppose gay marriage, and they are, by and large, a fecund bunch. That means there are more Will Portmans out there waiting to announce themselves. Republican Oklahoma Senator James Inhofe, who appallingly once took to the Senate floor with a photograph of his 20 children and grandchildren to brag that there are no gays in his family, might well have gay descendants that he doesn’t even know about. They owe it to the rest of us to follow Will Portman’s example and make their existence known.

(Josh Barro is lead writer for the Ticker. Follow him on Twitter.)