[Cross-posted at the Gay Couples Law Blog, which discusses same sex family law, estate planning, and taxes.]

Ted Olsen, the famous conservative lawyer for the gay couples in Perry v. Schwarzenegger, laid out what he called the “conservative argument for gay marriage” in this past weekend's Newsweek.

Because conservatives often say that allowing gay marriage would require an activist interpretation of the Constitution, Olsen spent time spelling out why it would not.

The Argument

Olson said that marriage is a Constitutional right:

The United States Supreme Court has repeatedly held that marriage is one of the most fundamental rights that we have as Americans under our Constitution. It is an expression of our desire to create a social partnership, to live and share life's joys and burdens with the person we love, and to form a lasting bond and a social identity. The Supreme Court has said that marriage is a part of the Constitution's protections of liberty, privacy, freedom of association, and spiritual identification. In short, the right to marry helps us to define ourselves and our place in a community. Without it, there can be no true equality under the law.

While the Court traditionally has considered marriage in terms of heterosexual relationships, Olsen said that “the underlying rights and liberties that marriage embodies are not in any way confined to heterosexuals.”

So Is That It?

No. Even though the Constitution guarantees equal protection under the law, both state and federal governments are allowed to deny equal protection if they have legitimate reasons for doing so. So what it comes down to is whether the federal government (and California, in regards to Proposition 8) has legitimate reasons for denying equal marriage rights to gay couples.

But Olsen said that the reasons that gay marriage opponents usually give are not legitimate:

• It's tradition. “Simply because something has always been done a certain way does not mean that it must always remain that way. Otherwise we would still have segregated schools and debtors' prisons.”

• States need to encourage procreation. “Preventing lesbians and gays from marrying does not cause more heterosexuals to marry and conceive more children. Likewise, allowing gays and lesbians to marry someone of the same sex will not discourage heterosexuals from marrying a person of the opposite sex.”

• It threatens the institution of marriage. “I have yet to meet anyone who can explain to me what this means. In what way would allowing same-sex partners to marry diminish the marriages of heterosexual couples?”

Not Everyone Agrees

Despite Olson's argument, some people say that marriage should still be left to the states. So even if a state doesn't have legitimate reasons for disallowing gay marriage, that doesn't mean that the federal government has to . Jonathan Adler, a professor at Case Western Law School, agreed with Olson that marriage would benefit gay families, but said:

I remain deeply skeptical of the constitutional argument.  I am unconvinced the equal protection clause requires states to recognize same-sex marriages, though I believe the federal government should recognize any marriage recognized under state law.

In other words, just because the federal government should recognize gay marriages performed by particular states doesn't mean it has to make all the states recognize them too.

This brings us to Perry v. Schwarzenegger, where defenders of Proposition 8 ban will try to show that California has legitimate reasons for unequal treatment.