Civil Unions and Social Capital
I hope that homosexual couples find the strength to take the Civil Union institution and build on it.
Some homosexuals don't see it that way. In the Connecticut vote that defined Civil Unions but also defined marriage as separate (my ellipsis):
Rep. Evelyn C. Mantilla (D), who said she is raising a child with her female partner, asked her colleagues not to "further write my second-class citizenship into our statutes." She voted against the bill, she said, because the (marriage) amendment passed.
Homosexuals, like everyone, want dignity and the respect of society. After persecution throughout history, they just seek normality and many see that as only coming through marriage.
The problem is that marriage is an institution that's there to deliver an economic good - strong and educated young adults. It ensures that babies are born and reared for the extended period that homo sapiens uniquely requires.
Marriage has a high cost to its practitioners. Economic sacrifice, the disruption of childbirth, sleepless nights, endless housekeeping, teenagers who act like they're French and a lifetime role as defender of the progeny. There are innate positives of course (pause to enumerate, brow furrowed) to balance the negatives. And successful nations also give status and benefits to good parents and impose sanctions on deadbeat ones.
Our societies (legislatures and judiciaries) have been undermining marriage since the start of the great disruption, and the results surround us - high crime rates, poorly socialized young people, damaged adults and (in the UK and Japan) a refusal to marry. So the last thing marriage needs is another bullet.
Now, some homosexual couples have gone down the route of rearing children. Either through adoption, or women conceiving children by men outside of their relationship. Getting this to work from the child's standpoint has to be really hard. As well as facing the problems of raising children who are not kin, they struggle to field the complementary skill sets that heteros bring to child rearing. Some will make it work, but most will not.
Civil Unions seem to be a decent alternative. They provide respect for homosexual relationships without imposing procreational expectations that those relationships are very unlikely to deliver.
If I were a homosexual activist, I'd take the institution of Civil Union and build it as something different from marriage but which gives another value to society. Right now our societies are bleeding altruism, and without that we're in for a tough time no matter how many kids we have and how smart they are. I'd argue that developing (for example) stronger models for altruistic behavior could build social respect for homosexuals infinitely better than trying to take over an institution they can only struggle in.