WASHINGTON - The debate over same-sex marriage has reached the U.S. Supreme Court.

The court is hearing arguments about the constitutionality of California's Proposition 8 and the federal Defense of Marriage Act this week. Part of the arguments will center on whether gay couples should be entitled to a range of benefits afforded to straight married Americans, such as health insurance.

The cases represent a battle over a traditional concept of marriage and the rights of families in same-sex relationships. One of the major issues facing the court is whether it can or should make a ruling to broaden the legal definition of marriage.

Some justices raised concern whether the case should even be before the court. Justice Anthony Kennedy, who is possibly the deciding vote in this case, suggests that the court could dismiss it with no ruling at all.

The high court is expected to reach a decision later this year.