|Bert and Ernie: just good friends|
The issue also hit the headlines last month when a US campaigner called for children's TV show Sesame Street to teach tolerance by marrying Bert and Ernie (pictured) - traditionally regarded as friends rather than romantic partners - prompting a petition in support and an insistence by Sesame Street producers that characters don't have any sexual orientation.
More seriously the issue has increasingly become a campaigning focus in the US, with victories for campaigns in a number of states including New York. But the demand finds considerable resonance in Europe too. Seven European countries now have legal same-sex marriage, while fifteen (including the UK) allow some sort of civil partnership.
It is important, in my view, to think through why gay marriage has become such a central issue for the LGBT movement. One extremely good reason lies in the nature of homophobic prejudice and discrimination.
Homophobia largely isn't about economic inequality. Women workers earn less than male workers; black workers earn less than white workers. Economic inequality is integral to these forms of division and oppression. The same inequality isn't there when comparing LGBT workers with heterosexual workers.
Homophobia has a great deal to do with what is socially acceptable, normal or legitimate. What LGBT people want is to be viewed and treated as equal by the society they're part of, and by the people in it. They don't want to be seen as abnormal, viewed with suspicion or subject to completely different social conventions.
This means being able to marry and adopt kids, but it's also about being able to hold hands in public without getting funny looks (or worse) and feeling confident about booking a room in a B+B without pretending you're 'just friends'. It's all sorts of things in everyday life, like being comfortable with talking about your relationship with work colleagues or a teenager being openly gay at school.
It's also about the whole emotional field that goes with this - not having feelings of shame and guilt, not keeping secrets from family, and so on. It's about LGBT people seeing themselves reflected and represented in media and culture, rather than being invisible or subject to ridicule. Political and social equality in the broadest sense is the aim.
In this context we can easily see why gay marriage has become a central issue and a rallying call capable of mobilising large numbers of supporters. It goes to the very heart of how homophobia works, as being married is socially mainstream. Not being able to marry reinforces a sense of marginalisation and 'otherness' relating to LGBT people. The issue thus becomes representative of much more than itself.
It's also a specific legislative change - one which crystallises a number of the issues I've referred to - so it is ideal for a protest movement. Every campaign needs something concrete to fight for.
Is it enough? No. But no kind of equality is enough within the constraints of a capitalist society. Socialists fight for liberation not just equality. This is a broader vision that connects specific issues for particular social groups to a larger struggle, in which the collective power of the working class (as the 'universal class') is decisive.
Whatever the constraints, it is essential to actively support struggles for equality. In the context of shared campaigning, a more radical and thoroughgoing vision of human liberation can be articulated.
Also see: The SNP's Gay Marriage Crisis