I realize from the distance of the UK and without the daily barrage that is the US news cycle the current position of marriage equality here in the US may be confusing. Frankly its pretty complex from here. So for those puzzled by the recent flush of red user pictures on Facebook, or wondering why the Daily Mail is having a fit about someone getting smacked in the face I will attempt to clarify.
To understand this we have to consider a little bit of the US federal system. Keeping it simple (and making my lawyer friends cry with the simplification) there are three levels of "law" in the United States: State, Federal and Constitution.
Every State is free to make its own laws, these are decided by state lawmakers and signed into law (or not, but that's another matter) by that state's governor. These laws can be completely different to the laws of the next door state. For example I live in New Jersey, where if you come to a stop at a red light, and there is not a sign saying you can't do it, it is completely legal to turn right without waiting for the green light. A few miles away in New York this would be illegal, trust me on long journeys this gets confusing.
However, due to the overlapping jurisdictions of the Federal and State government State laws rarely win when they clash with Federal law (that is law created by the United States Government) an example being Colorado, which recently legalized the possession of marijuana, but since Federal law still bans it the reality is that you can still be prosecuted for carrying it. Federal laws are created by the lawmakers in Washington DC and signed into law by the President, they apply everywhere,
Confused yet? Stay with me.
Finally the highest law in the land is the US Constitution This document has been revised no less than twenty-seven times and forms the framework that no law is allowed to contradict. With the 14 amendment this has included state law as well. This is the final decider, the only way to pass a law that contradicts the Constitution is to change the Constitution. This law is decided on by Federal Judges who decide if a law is, or is not, allowed, there are several levels of these judges, local, regional, and finally the supreme court. Obviously it is really about the judges interpretation of the constitution in each case, if you don't like the interpretation of your local judge, you'll probably appeal to the next level up hoping they rule your way.
The reason for all the to-do yesterday and today was the US Supreme Court finally ruling on two cases, deciding whether two laws were allowed by the constitution.
In May 2008 the courts in California (state court) ruled that Californian law allowed gay couples ot marry. This was a huge decision and allowed gay couples to marry for the first time in the United States. Later that year a well organized and well funded move put the matter up for a public vote - this was called "Proposition 8," the people of California voted to change the law and ban same-sex marriage. Many couples who had been married were suddenly... not married? Maybe married? Who knows.
As the comment below notes, they were still legally married, but that in itself was a whole fight.
A group including two of the leading lawyers in the country Ted Olsen and David Boies (previously opponents in the landmark Bush vs. Gore case that decided the 200 Presidential Election) organized to take this to Federal Court saying it violated a clause in the Constitution that says everyone in the US gets "equal protection" under the law. At the local and regional levels they were successful in having proposition 8 rules unconstitutional. On Tuesday the case finally reached the Supreme Court. By this time many people had joined their side, in fact the case was argued before the nine Supreme Court justices by Ted Olsen, and the current Solicitor General representing the President.
The signs suggest that the Supreme Court will probably say they will not decide on the constitutionality of proposition 8, because they think the anti-marriage equality activists who brought the case do not have "standing" to do so. Since it is a Californian law the court will say that the governor of California (in a bizzaro world moment when it was passed this was Arnold Schwarzenegger, no really THAT on.) should be the one bringing the case, since the governor does not wish to defend the law, they will argue it cannot be brought to them and so they will throw the whole thing out. This will mean the previous ruling against Proposition 8 will stand and same-sex marriage should be legal again in California.
By doing this they avoid making a far reaching ruling that would either ban or make legal gay marriage for the whole country.
The Defense of Marriage Act was passed into Federal law in 1996, it is a very simple and very nasty little bit of work. It ensures that the US government only recognizes opposite sex marriages, denying any of the advantages in terms of tax, inheritance, hospital visitation rights, etc. It also blocks states from recognizing marriages from other states. Federal law currently rules that if you're married in Wisconsin you are also married in Michigan, However, DOMA prevents that from applying to same-sex marriages. Even though you can get married legally in New York, if you cross the Hudson River into New Jersey you are magically unmarried here. (Not as fun as it might sound.) The woman bringing the challenge to this is Edith Windsor, she was married to her partner of 40 years in 2007, in Canada. When she passed away in 2009 New York (where they lived) had a law recognizing same-sex marriages from other places (despite the issues this would have with DOMA, this kind of State/Federal clash happens a lot) but Edith had to pay out over $350k in taxes on her wife's property when she inherited it. Something an opposite sex spouse would not. The case again rests on the fact that the US Constitution does not allow you to treat one group differently to another - "equal protection." The legal background of this has its roots in slavery.
This case again involves the people you would expect to defend the law, the President's Justice Department, not defending it. Instead the Republican lawmakers in congress footing the bill to fight for this bigotry.
The chances of DOMA being repealed look pretty good. The anti-gay bigots have to argue that the Federal Government has an interest in keeping marriage as only opposite-sex the outweighs the constitutional issues. This seems unlikely, in fact the questions being asked by some of the justices seem to indicate they will rule DOMA out.
While the news from the court today suggest how these cases will be ruled, we wont know the actual verdict for quite some time.
All this comes at an incredible moment for the gay rights movement. Support for marriage equality has shifted incredibly dramatically in the last ten years. Recent polling showing over 60% of Americans support some sort of unions for same-sex couples. With the current President and the lady very likely to be the next democratic nominee both in full support of full marriage equality, and even the head of the Republican party suggesting that his party wants the votes of marriage supporters (it's just not willing to do anything to get them yet), it is an incredible moment in US politics.