Yesterday was a banner day for the "Marriage Equality" movement in the United States. In United States v. Windsor, the Supreme court struck down the federal "Defense of Marriage Act," (DOMA) a 1996 law which defined "marriage" as a union between a man and a woman for purposes of federal laws.
When it was enacted, DOMA really just codified the status quo; no jurisdiction had yet recognized marriage between partners of the same sex. The law was a preemptive strike at a time when the earliest gay marriage cases were under consideration in the Hawaiian courts. The situation now is vastly different.
Marriage equality, defined as recognizing same-sex marriages in the same way as opposite-sex marriages, has been gaining steam for the past decade. As recently as ten years ago opponents of same-sex marriage could claim the "will of the people" was against marriage equality, because no state had legislatively granted same-sex marriage rights and many states had passed laws or constitutional amendments banning the practice. However, in the past year Maine, Delaware, Maryland, Minnesota, Washington, and Rhode Island passed laws to allow for same-sex marriage. This brings the total number of marriage equality states to twelve, plus also the District of Columbia. According to the advocacy group Marriage Equality U.S.A., 18% of all Americans, and 22% of all same-sex couples now live in states which allow same-sex marriage. An additional 9 states have provisions for "civil unions" or similar legal recognition short of marriage for same-sex couples. This includes my home state of Illinois, which recognized "civil unions" in 2011, but let a bill for full marriage equality die in the House of Representatives this term.
This same pattern is seen across the globe. In Mexico and Brazil, which have federal systems of government similar to the U.S., some states have begun recognizing same-sex marriages. Other Western Hemisphere countries including Canada, Uruguay, and Argentina have passed laws at the national level extending marriage rights to same-sex couples. This is also the trend in Europe, where eight countries recognize full marriage rights and many others give some more limited legal status to same-sex couples. New Zealand and South Africa also extend full marriage rights to same-sex marriages.
Now that DOMA is history, same-sex couples who were legally married in any of these jurisdictions, or others which might later approve such marriages, will qualify to file federal income taxes jointly, and claim any number of government benefits, tax deductions, and exemptions granted under federal laws. Most notably for my line of work, Secretary of Homeland Security Janet Napolitano was quick to announce that her Department would implement the decision "so that all married couples will be treated equally and fairly in the administration of our immigration laws."