The judge deciding the Proposition 8 case should recognize that the arguments advanced against same-sex marriage fall short.

What is the rational basis for laws that deprive gay and lesbian couples of the right to wed? The arguments that have emerged so far — that same-sex marriage is bad for child-rearing and that it damages heterosexual unions — fall apart under the slightest scrutiny. A judge in Massachusetts recognized this in a case involving the federal Defense of Marriage Act; now the judge in the lawsuit against California’s Proposition 8 should do the same.

In declaring the federal marriage act unconstitutional last week, U.S. District Judge Joseph Tauro noted that when Congress passed the law in 1996, supporters said it would “encourage responsible procreation and child-rearing” and protect traditional heterosexual marriage. The law recognizes only heterosexual marriage for federal purposes. Supporters of Proposition 8 used almost identical language during the 2008 campaign to ban recognition of same-sex marriage in the state.

In this year’s trial on the proposition, however, even its defenders were unable to show that same-sex marriage threatened the traditional institution of marriage. And not only is there ample reason to doubt that the children of gay and lesbian couples are any worse off than those in traditional families, that’s not reasonable grounds for denying marriage based on sexual orientation. Many people make less-than-ideal parents. They aren’t denied a wedding license because of it.

Read the full piece here.