Richard Wolf, USA TODAY
WASHINGTON -- A divided Supreme Court gave a major boost to gay and lesbian rights on Wednesday, striking down a key section of a federal law that denied federal benefits to legally married same-sex couples.
The justices declared unconstitutional part of the 17-year-old Defense of Marriage Act, a law that has denied federal benefits to married gays and lesbians in a dozen states, from Maine to Washington, and the District of Columbia.
The decision gives the high court's blessing, at least in part, to a gay-marriage movement that has gained momentum in the past decade and now stands on the threshold of full equality. The ruling represents a major step forward for marriage equality and a setback for defenders of traditional marriage between only men and women. But 36 states still ban same-sex marriage, and the high court's ruling doesn't affect them.
READ THE OPINION: United States v. Windsor
PROP 8: Coverage
In a 5-4 decision written by justice Anthony Kenedy, said the federal law unconstitutionally denied equal treatment to gay and lesbian couples. "DOMA singles out a class of persons deemed by a State entitled of recognition and protection to enhance their own liberty," Kennedy wrote.
But Kennedy wrote that the decision was "confined to those lawful marriages" performed in states that already recognize same-sex marriage.
Kennedy was joined by the court's four more liberal justices. The court's conservative justices dissented.
The Defense of Marriage Act has two main sections, only one of which - defining marriage in federal laws as between a man and a woman - was contested. Because of it, benefits and programs enjoyed by opposite-sex couples aren't available to gays and lesbians under federal employment, health, tax and other laws. The other provision shields states from having to recognize gay marriages from other states.
Attorney General Eric Holder announced in 2011 that the Obama administration considered DOMA unconstitutional and no longer would defend it in court. Into the breach stepped House Republicans, who argued - to no avail in lower courts - that the law saves needed federal resources and ensures they are distributed equally among the states.
At last count, there were more than 1,100 provisions in federal laws that listed marital status as a factor in determining benefits, rights and privileges. The list, prepared by the Government Accountability Office, was most recently updated in 2003.
The most prevalent are tax laws. Despite their marriage certificates, gay and lesbian spouses cannot get tax-free health benefits from their employers. That alone costs them about $1,000 a year on average, says Gary Gates, a demographer who studies gay and lesbian trends at the UCLA School of Law's Williams Institute.
Gays and lesbians can't file joint federal tax returns, as heterosexual married couples can, which often saves families thousands of dollars. If gays or lesbians divorce, any alimony is considered a gift subject to taxation, while for opposite-sex couples, it's tax-free. And when a spouse dies, the widow or widower is liable for inheritance taxes; heterosexual couples enjoy a marital deduction.
That estate tax problem is what prompted Windsor to file her lawsuit. She stands to win back the $363,000 she paid in 2009 on the estate of her deceased spouse, Thea Spyer - a tax she would not have owed if their marriage was recognized by the federal government.
A few dozen other same-sex married couples, widows and widowers also stand to gain because they had filed legal challenges or tax claims that have not expired, says Mary Bonauto, civil rights project director at Gay & Lesbian Advocates & Defenders. For all other same-sex married couples, the impact of the court's ruling would be prospective, not retroactive.