Social Darwinism. Men-evolved-from-apes, all change is inevitable and onward and upward. Our benighted ancestors didn't know about gay rights, poor ignorant fools. Now, with societal progress, we know better. Social evolution. Moral relativism. The only absolute truth is that there is no absolute truth.
Since it's inevtiable, lie back and enjoy it, or at least tolerate it.
It is our duty, our right, and our only real happiness to fight for what is the natural law of the universe. The alternative is chaos in our time.
Do we today live in the same society that the Founders did, under the same morakl standards?
You wouldn't live there.
They would be scandilized at our society in general, not just the gay thing. Society moves forward, and there's plenty of proof of that available.
Where's slavery? Where's Jim Crow?
Where are the hippies?
Everything changes.