I never said this was my view, so please calm down.
Now:
Adoption is mostly irrelevant as it does add to the population. Adoption rates won't increase likely much with gay marriage being legalized, and it would take a large increase to lower the funding for adoption agencies (which are far below standard anyway).
IVF and artificial insemination are valid points, but I don't believe that the ratio of gay couples getting this (especially multiple times) is going to be anywhere near the ratio of straight couples getting it.
Population overgrowth isn't a direct problem at the moment. In 100 years the expected population is to be handled well by the planet. In 200 years is when a problem seems to arise. However, by then to assume that at the rate our technology is advancing that we haven't had any major wars that significantly hurt population or that we haven't begun inhabiting other planets seems poor judgment.
DarkRyter said:
The rights to equality before the law > Welfare of the State.
No one is being given more rights than others. I could say that I and my few thousand friends here only want to marry people who are on Death Row. If someone is on Death Row, and they get married, is not for the happiness of the innocent partner to not kill the other? I see your point though, I don't fully agree that the State is second to the people always; as the state is the people, and the people are the state.