It's a basic law of the universe.
It's been proven for centuries through math and science.
Two things that are equal to the same thing must be inherently equal to each other.
Any two people- despite race, gender, religion, sexual orientation, etc.- are humans.
Humans must be equal to each other.

This might be a quote from the movie Lincoln or it might be my brain being beautiful, and I'm not sure which one it is.