"I'm afraid the 'put the word black in place of gay' argument doesn't work - black is simply a skin colour - gay represents practicing certain acts which the Bible explicitly states are not acceptable.Your argument would indeed work if you replaced the word 'gay' with something else that the Bible clearly states is not acceptable such as 'murder'(ers)."
The Bible does not "clearly state" that homosexuality is a sin, it's a point of much debate.
However it is pretty clear about the ten commandments.
But the Catholic Church doesn't want to be able to ignore the law regarding adulterers, liars or people who work on Sunday.
Likewise the Bible is pretty clear that sex belongs in marriage.
But the Catholic Church doesn't want to be able ignore the law regarding people who live in sin.
The Catholic Church itself is very clear on it's stance on contraception.
But it doesn't want to be able ignore the law regarding people who use it.
Among all those sins and sinners the Church wants to ignore the law on one very particular issue, homosexuality.
And that is, to say the least, curious.