Then argue for individual "transcendent liberty" for all. Take a position, any position.
Now, you cite the Constitutional passage that grants the Federal government the power to deny Mormons the right to engage in polygamy.
You're confused Luis, I believe in a republican form of government for all the states as the Constitution requires. You are the fellow arguing in favor of judicial fiat from a central authority. Try to keep the scorecard straight.
Not at all, you are (as usual) defining the laws of the land as something which can be used to deny others of a right that you enjoy...in this case is that right of marrying the poerson of your choice (I am assuming that you are a heterosexual).
This argument (State's rights) always is used to argue in favor of laws which oppress the rights of some, and against legislation/judicial decision which go against those laws.
We are all two things, the most important pof which is "Americans" and as such, protected by the US Constitution from having our rights violated. States neither have the power or the right to violate someone's Constitutional rights.
And you also apparently believe that US citizens can have their Constitutional rights violated by the States.
Civil unions, the rite performed by a government licensed magistrate, cannot be limited by moral values predicated by the religious beliefs of any segment of the population, the Constitution forbids the government from engaging in such restrictions.
Holy Matrimony, the rite performed by members of the clergy, is not subject to governmental regulations, and as such, Churches cannot be mandated to perform gay marriages.
Clear enough for you?