Straw Man Arguments

They say that no one will hold a gun to someone's head and force them to perform a marriage.
That won't happen.
What will happen is a pair of homosexuals will seek out an extremely conservative bishop, someone high ranking in the church.
Then, they will ask him to marry them.
He will rant and rave at them, and all of this will be in public.
Huge public support for the couple will surge, and the Catholics will be regarded as homophobes and sticks in the mud.
I'm honestly scared to see this happen, and I think it's likely.
Just because the Catholic Church doesn't support gay marriage, they provide a huge number of social services, only behind the Salvation army. If they lose credibility, the effects could be potentially devastating.