Do you deny that the entire understanding of marriage in this country, without even referencing its long traditions elsewhere, was that it was between one man and one woman? [Maybe, got evidence?] If you deny that, then there is hardly a reason for me to argue for why changing it was done in an un-Constitutional manner.
Oh, yes, yes there is! It's called a "
non sequitur", a logical fallacy. I know you are familiar with that, because you use them so often. I can already tell where this is going to go, but... let me try something.
I suppose you know the current Constitution was not the original organizing document for the United States, right?
First there were the
Articles of Confederation. (Okay, if you want to get technical, the Declaration of Independence occurred before that.)
The Continental Congress adopted the Articles of Confederation, the first constitution of the United States, on November 15, 1777. However, ratification of the Articles of Confederation by all thirteen states did not occur until March 1, 1781. The Articles created a loose confederation of sovereign states and a weak central government, leaving most of the power with the state governments. The need for a stronger Federal government soon became apparent and eventually led to the Constitutional Convention in 1787. The present United States Constitution replaced the Articles of Confederation on March 4, 1789.
The second Constitution (which we now use), created, instead, a much stronger central government. That was the argument of "the Federalists", and much of
The Federalist Papers , the majority produced by Alexander Hamilton. There were, of course, tensions between the "Federalists" and "
Anti-Federalists" (later the "Democratic-Republicans"). Ultimately, those tensions resulted in
the Civil War, after which secessionist States were brought back into the Union. It also resulted in the 13th,
14th, and 15th Amendments to the Constitution. Of import, here, is Section 1:
No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
(You see where this is going, right?)
Apparently, also, you have forgotten about the
Ninth Amendment. "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people."
So, from my perspective (and, frankly, that of the Constitution itself), people have the
inherent right to marry whomever they want, and to prevent that, a government (State or national), has to have a compelling reason to prohibit it. Tradition, or religious proscriptions don't cut it. You ask the wrong question, if you are asking why it is allowed under the Constitution. Rather, the question should be: How is it prohibited?