Justice Ginsburg cited a key moment in women's rights to make a point about gay marriage

During the Supreme Court's oral arguments Tuesday in a landmark case over same-sex marriage, liberal Justice Ruth Bader Ginsburg asked probing questions of a lawyer arguing against gay marriage.

That lawyer, Michigan Solicitor General John Bursch, argued that the one man/one woman definition of marriage has existed "for millennia," echoing a statement made earlier by Justice Anthony Kennedy. Changing that definition could hurt America's children, Bursch emphasized.

But Ginsburg shot back that we have already "changed our idea about marriage."

"Marriage today is not what it was under the common law tradition, under the civil law tradition," she said. "Marriage was a relationship of a dominant male to a subordinate female."

That all ended about 35 years ago when the Supreme Court finally struck down Louisiana's Head and Master Law, which said men have the right to all property in a marriage.

In the current gay marriage case, one of the key questions is whether states can ban gay marriages - specifically looking at bans in Michigan, Kentucky, Ohio, and Tennessee.

On Tuesday, Ginsburg pointed out that states couldn't have marriages where men and women were unequal after the high court found such marriages were unconstitutional.

"Would that be a choice that a state should be allowed to have? ... To cling to marriage the way it once was?" Ginsburg asked, suggesting that states shouldn't be able to define marriages in ways that violate people's constitutional rights.

Bursch responded "absolutely not."

Here are the two constitutional questions at the heart of the current gay marriage case:

1) Does the Fourteenth Amendment require a state to license a marriage between two people of the same sex?

2) Does the Fourteenth Amendment require a state to recognize a marriage between two people of the same sex when their marriage was lawfully licensed and performed out-of-state?

That amendment guarantees Americans "equal protection under the law" and the right to "due process of law."

A decision on the case is expected in June.