Who should be able to marry? The Supreme Court may ultimately decide the fate of same-sex marriage.

• Author: Smith, Patricia
• Position: NATIONAL

Last summer, when New York became the sixth and largest state to legalize same-sex marriage, Governor Andrew Cuomo urged other states to follow New York's lead.

"We need marriage equality in every state in this nation," he said. "Otherwise, no state really has marriage equality, and we will not rest until it is a reality."

But in Minnesota, where voters will face a ballot question this November asking if the state's constitution should be amended to prohibit same-sex marriage, advocates of the ban see the issue very differently.

"I just believe very firmly that marriage is between a man and a woman," says Greg Davids, a Minnesota legislator.

For more than a decade, the issue of same-sex marriage has been a flash point in American politics, setting off waves of competing legislation, lawsuits, court rulings, and ballot initiatives to either legalize it or ban it.

In February, Washington state legalized same-sex marriage, becoming the seventh state to do so, along with Washington, D.C. And the Maryland House of Delegates passed a bill legalizing same-sex marriage that appeared headed for approval by the state Senate. (The New Jersey legislature also passed a law allowing gay marriage, but it was vetoed by the governor.)

Five other states have passed civil union laws, giving gay couples all the legal rights of marriage under a different name. But many have moved in the opposite direction: More than 30 states have either constitutional bans against gay marriage or laws prohibiting it (see map).

California & Prop 8

Proponents of same-sex marriage see it as a civil rights issue: Gay people, they argue, should have the same right to marry as everyone else, especially since many legal rights and family protections are tied to marriage. Opponents say allowing same-sex couples to marry would undermine the institution of marriage, which many see as a religious rite going back thousands of years.

The up-and-down fortunes of gay marriage in California show how determined both sides are on this issue: The state had a long-standing law prohibiting same-sex couples from marrying, which was declared unconstitutional by the state Supreme Court in 2008. Six months later, Proposition 8--a ballot initiative to amend the state constitution to ban same-sex marriage--passed with 52 percent of the vote.

Gay-marriage supporters there sued to block the voter-approved ban. Last month, a federal appeals court ruled that the ban is unconstitutional, setting the stage...