If traditional marriage is redefined by socially liberal people, there will be a new definition of marriage.
Once it is redefined, it can be redefined again. I'm not saying that marriage would be redefined again, but it is very possible. I imagine if the idea of same-sex marriage were floated even in the 1960-70's people would be appalled. See how times change?
If marriage were re-defined, it would open the door to polygamy and plural marriages.
Homosexuals and lesbians could marry were marriage re-defined, but bisexuals - to an extent - could not.
I imagine that, sooner or later, they (at least some) would be screaming to be allowed the right marry the two people they love (both male and female).
Polygamists would be screaming for the right to legally marry were marriage re-defined. They already are, in fact. Gays certainly don't want to talk about that happening.
In the context of same-sex marriage, socially liberal people often bring up African-Americans not being allowed to marry whites (and vice versa) at one time. But that is comparing apples to oranges. One is born black. It is genetic. Homosexuals are not "born that way." Homosexuality is not genetic, and attempts to find a genetic link to homosexuality or a homosexual gene, have failed. The top minds on this say that there is no homosexual gene.
Additionally, socially liberal people often say that DOMA is a violation of either the 4 or 14th Amendment. But, if one looks closely at those two Amendments, DOMA does not violate them at all.
Socially liberal people often say that DOMA, or bans on same sex marriage, are 'tyranny of the majority'.
Wanting to re-define marriage (via the courts) to allow homosexuals to marry, plural marriages, or polygamy is tyranny of the minority then. They continue to try to ram this issue down our throats.
Why must gay activists, liberal Democrats, and socially liberal people be so divisive?
PING
So in other words infertile people who are planning to adopt one or more of the many unwanted children out there shouldn't marry?
I have a friend who got married in 1992. She knew they wouldn't be able to have children biologically together as she had to have a hysterectomy at age 12.
They adopted one little girl from China and a little boy from Russia.
In this law they wouldn't be able to marry.
But 2 other couples I know who got married the month they did (Busy expensive month for me!) who had kids together the usual way divorced before their 3rd anniversary.
I guess a "woman's right to choose" is unimportant if it infringes on their agenda.