"Therefore, acceptance of same-sex marriage is Constitutionally required."
Is THAT a fact?
Perhaps we're talking of two distinct documents because the USC I'm familiar w/ contains no such requirement.
The USC is not a suicide pact that requires us to destroy the social fabric in the name of "fairness". If you do not understand the foundational nature of heterosexual marriage and its necessity for the maintenance of society then I'm afraid that you are a dunderhead and that any further argument is pointless.
Under the USC, there is no such thing as "social policy" to begin with. It's a name for a classification invented by federal courts to accommodate extra-Constitutional activities by the federal government. In terms of individual rights and protection against arbitrary government policy, it's equivalent in stature to fiscal policy. You have no individual right that will get your tax rates declared unconstitutional; except under "equal treatment" - doesn't matter whether you find that exact phrase in the Constitution or not. The term "social policy" is used when referring to welfare programs. A welfare recipient can similarly not have their entitlements increased by Constitutional argument - except for equal treatment.
The transition to social policy from civil law was a redefinition of marriage from a sacred private institution to an element of government welfare programs; where equal treatment (equal entitlement to government program benefits) arguments apply.