During my lifetime, our country has made great progress in eliminating discrimination. Although there is much more to be done before we have fully eliminated racial, religious, gender and ethnic discrimination and have begun to fulfill the promise of equality upon which our nation was founded, only one group of our citizens – gays and lesbians – is still subject to official, state-sponsored, state-enforced discrimination.

One of the most invidious of the state-sponsored discriminations against gays and lesbians is the prohibition of gay and lesbian marriage. As the U.S. Supreme Court has repeatedly held over more than a century, marriage is one of our most important personal relationships, and the freedom to marry the person of your choice is protected by constitutional guarantees of liberty, the right of association and due process.

Thus, in 1978 the court held unconstitutional a Wisconsin law preventing child-support scofflaws from remarrying. In 1987, the court unanimously struck down as unconstitutional a Missouri law preventing imprisoned felons from marrying. Legitimate state policies supported the Wisconsin and Missouri statutes. The Missouri law in particular was defended on the grounds that since imprisoned felons are unable to have any physical contact with their spouses, let alone live with them, such a marriage could not serve what was claimed to be the “traditional” purposes of marriage, including procreation. The court rejected those arguments, emphasizing in the Wisconsin case that “decisions of this Court confirm that the right to marry is of fundamental importance for all individuals” and in the Missouri case that marriages were constitutionally protected “expressions of emotional support and public commitment.”

In 2008, the California Supreme Court held that gay marriage was a fundamental right protected by the state Constitution. Later that year, Proposition 8 intended to take away that right by amending the state Constitution. Last year, Ted Olson and I brought a lawsuit on behalf of couples who were denied marriage licenses as a result of Proposition 8 to declare the state’s prohibition of gay marriage unconstitutional under the U.S. Constitution.

At the beginning of the trial in January, we said we would prove three propositions:

First, that marriage is a fundamental right – a proposition with which even the defendants agreed. This is important because we are not asking the courts to establish a new right, only to hold that an existing right cannot be denied based on sexual orientation.

Second, we proved that depriving gay and lesbian couples of the right to marry seriously harmed them – and seriously harmed the tens of thousands of California children they are raising – economically, socially and psychologically. We also demonstrated that when the state decrees that a gay or lesbian relationship is not worthy of being sanctified by marriage, it sends a dangerous signal to some people that they are second-class citizens to be disapproved and perhaps feared and that discrimination and even physical harassment could be justified. Although the defenders of Prop. 8 initially sought to argue that domestic partnerships are an adequate substitute to marriage, at trial even the defendants’ own expert on cross-examination conceded, demonstrated by consistent expert and empirical evidence, that they are not.

Third, we said we would prove that the defendants’ claim that permitting gay marriage would somehow undermine heterosexual marriage is entirely bogus. This is a matter of both common sense and experience. After all, what heterosexual couple do you know of who would decide not to get married because their gay neighbors can get married? Moreover, countries as Catholic as Argentina and Spain, as different as Sweden and South Africa and as near as Canada have embraced gay marriage without any noticeable effect – except the increase in human happiness and social stability that comes from permitting people to marry for love.

At trial, we went further, demonstrating by uncontradicted evidence that permitting gay marriage strengthens, not weakens, the institution of marriage and the goals it serves. Even the defendants’ expert agreed that he had no evidence to support the defendants’ claims, and defendants’ counsel had to admit he simply “did not know” what effect, if any, gay marriage would have on the institution of marriage.

Read the full piece here.