A year ago, gay couples weren’t allowed to have sex in Texas. As of today, those same couples can move to Massachusetts and get married.

As they say in “Rent,” how do you measure a year?

Here’s the front page of today’s Boston Globe: “Free to Marry.” And here’s Howard Dean on gay marriage, also in today’s Globe.

You know, I’m realizing that gay Vermonters have basically been able to do for the last four years what gay Massachusetts residents are able to do as of today, except that it’s called something different. Both states now grant gay couples all the same rights as straight couples, and neither arrangement is recognized by the federal government. There was a lot of criticism a few months ago that calling such an arrangment a “civil union” as opposed to a “marriage” would have set up a scheme that was supposedly “separate but equal,” a concept that was deemed a failure 50 years ago today. But would it really be unequal?

In school segregation, separate was unequal, but that was because all-blacks schools didn’t receive the same funding and support as all-white schools and were therefore patently inferior. One benefit of integration was supposed to be that racist local governments would no longer be able to provide benefits to white students without also granting them to non-white students, because the students would all be mixed up in the same schools. In other words, it wasn’t the lack of white people per se that made black schools inferior, but rather the unequal funding and attention given to all-black schools. In fact, there are liberals today who disagree with Brown, who support the idea of separate schools for blacks as a way of instilling racial pride and identity. There are also those who think that Brown would have been better decided had the Supreme Court instead chosen to rigorously enforce “separate but equal,” which would have forced states either to create equal schools or just cry “Uncle” and integrate.

The point, anyway, is that it is not separateness itself that creates inequality, but rather the way that that separateness is dealt with. Vermont civil unions and Massachusetts gay marriages are completely the same, as I mentioned above. The only way they could be treated unequally is if the federal government someday recognizes all marriages, gay or straight, leaving Vermont “civilly-united” couples in the dust. But I think that if the federal government (whether of its own volition or under order of the U.S. Supreme Court) takes the big step of recognizing gay marriage, it will be such a seismic shift that there will be no logical or psychological reason not to recognize civil unions as well. After all, it’s just semantics. We’re talking about marriage as a civil institution (courts can’t force churches to do anything), so does it really matter whether a governmentally-recognized same-sex relationship is called a civil union or a civil marriage?

To some degree, yes. The real legal breakthrough might have occurred four years ago in Vermont, but today has great symbolic value. First, it just feels wonderful to think that there are now legally-married gay couples in the United States. Second, symbolism can lead to substance, because symbolism can affect the way people think about things. Calling legal gay relationships “marriage” forces people to think about equality and gay relationships, and it really puts the idea out there for people to see.

The causes of change are really murky. As one of my law professors argues in today’s Times, Brown did not lead to integrated schools; a shift in society’s views was first required. But a court decision can affect society’s views. Change occurs due to lots of “soft” factors. It wasn’t the Goodridge decision alone that led to legal gay marriage in Massachusetts, but rather Stonewall, the AIDS crisis, Rock Hudson, Clinton’s 1992 courting of the gay vote, Ellen DeGeneres, Matthew Shepard, and Lawrence v. Texas, as well as lots and lots of people coming out of the closet and thereby enlightening their families and friends, as well as lots of other things that are unmeasurable, that led to today.

So the word is not necessarily crucial, but it does matter. Civil unions are not inherently unequal, and marriage does not make everything equal. The word does not automatically make other people respect you or your relationship. But it’s one of those little things that, combined with other things, eventually creates change. You can’t control change — it’s like chaos theory. But you do what you can.

Therefore, congratulations, all you happily-married gay couples!

And save me some cake.