Vaughan's Law

In any discussion about marriage, the moment a proponent compares gay marriage to the civil rights era, the argument is automatically forfeited.

Person #1: "I believe marriage is between one man and one woman."
Person #2: "Well how would that have worked in the civil rights era?! Loving v. Virginia says we all have equal protection, you're just substituting Jim Crow for Tim Crow!"

Person #1: "I invoke Vaughan's Law."
Person #2: "Dammit... you win...