Why do you only therefore choose to fight for bestialitist, polygamists, and incestualists?The liberal argument for gay marriage is that not allowing it is discrimination, and that discrimination is wrong.
Therefore pointing out other groups who are discriminated against with regards to marriage is quite important.
Why are liberals only fighting some discrimination?
Do you have an affinity to those discriminated parties?
The list of groups that "theoritically" are being discriminated against could be quite long..if we want to go down this illogical reasoning
I want to marry a Star in the Milky Way Galaxy. I'm being discriminated against
I want to marry the color Blue
I want to marry my baby teeth
I want to marry the Golden Gate Bridge
I want to marry Santa Claus
I want to marry Elvis
I want to marry the LA Lakers Organization
This is why we have logic and reasoning and critical thinking skills. To keep rift raft fallacies from clouding the issue.
Focus on why gays can/cannot be legally married.
IF you wish to see polygamists etc be legally married, take the issue to court.