When the Supreme Court listens to arguments about same sex marriage Tuesday in what is expected to be an historic case, sitting in the audience as a guest of Chief Justice John Roberts will be his lesbian cousin.

In an open letter distributed by the National Center for Lesbian Rights, Jean Podrasky writes, "Tomorrow, my cousin, the Chief Justice of the U.S. Supreme Court, will begin considering the fate of two of the most important cases impacting the rights of the LGBT community ever to go before the Court-the challenges to California's Proposition 8 and the federal Defense of Marriage Act (DOMA). "

"I want nothing more than to marry my wonderful girlfriend," states Podrasky, who lives in the San Francisco area.

"I know that my cousin is a good man. I feel confident that John is wise enough to see that society is becoming more accepting of the humanity of same-sex couples and the simple truth that we deserve to be treated with dignity, respect, and equality under the law.

"I believe he understands that ruling in favor of equality will not be out of step with where the majority of Americans now sit. I am hoping that the other justices (at least most of them) will share this view, because I am certain that I am not the only relative that will be directly affected by their rulings," Podrasky wrote.

Podrasky is the latest gay or lesbian person revealed to be related to or friends with a powerful politician, and the sense that everybody knows someone who is gay is affecting the political debate over gay rights and gay marriage.

When President Obama endorsed same-sex marriage on May 9, 2012, he said, "You know, Malia and Sasha, they've got friends whose parents are same-sex couples. And I -you know, there have been times when Michelle and I have been sitting around the dinner table. And we've been talking about their friends and their parents. And Malia and Sasha would-it wouldn't dawn on them that somehow their friends' parents would be treated differently."

Sen. Rob Portman, R-Ohio, announced earlier this month that he had changed his position on gay marriage in light of his relationship with his gay son.

"Then something happened that led me to think through my position in a much deeper way. Two years ago my son, Will, then a college freshman, told my wife, Jane and me that he is gay," he said.

Before the Portmans, there was Dick and Mary Cheney, though that did not change much policy-wise in the Bush White House.

Cheney and his wife on the day of their daughter's wedding in June 2012 issued a statement that read, "Our daughter Mary and her long time partner, Heather Poe, were married today in Washington, DC. Mary and Heather have been in a committed relationship for many years, and we are delighted that they were able to take advantage of the opportunity to have that relationship recognized…Mary and Heather and their children are very important and much loved members of our family and we wish them every happiness."

Massachusetts Gov. Deval Patrick has advocated for rights for same-sex couples, knowing his daughter, Katherine, was a lesbian.

"First of all, we've had so many people in our lives whom we love who are gay or lesbian, so that's not that unfamiliar to us…You know, I can still - because we live in Massachusetts - I can still imagine what Katherine's wedding is going to be like," Patrick said in June 2008.

The effect of the modern family stretches beyond blood relatives to the politicians friends.

Sen. Claire McCaskill, D-Mo., explained Sunday why she has switched her stand.

"My views on this subject have changed over time, but as many of my gay and lesbian friends, colleagues and staff embrace long term committed relationships, I find myself unable to look them in the eye without honestly confronting this uncomfortable inequality," McCaskill said.