I don’t believe it’s down to the “persuasive” argument. The Founding Fathers knew of the struggle to maintain morality right from the start of the USA, after all.
Do the right thing. Stand for the truth.
Facts are not a popularity contest.
Clearly, Madison believed that neither government nor populace were peopled by angels. To the contrary both government and those governed are not angels. The problem can arise when those who govern conceive themselves angels and seek to control the baleful behavior of the governed, especially when those who govern forget that they themselves are no angels. Or, a problem can arise when those who govern believe they have the power of divine angels to change human nature.
One might observe that if all men were angels there would be no need to change human nature but since men are not angels is takes a power higher than man or man's government to change human nature and make angels of men.
Are our laws, what's left of them, against sodomy and sodomistic marriage designed to control behavior or to change human nature? Homosexuals tell us that that is the wrong question because it is natural for a homosexual, they say, to commit sodomy and no law can change that essential fact of their human nature. We have thousands of years of laws to do just that but we have failed wherever we have tried.
Here endeth the lesson of humility for the powers of government.