Our Constitution is color-blind, and neither knows nor tolerates classes among citizens

Plessy v. Ferguson, Dissenting Opinion, John Marshall Harlan

The lone dissent in one of the more disreputable decisions ever passed. The words ring clearly more than a century later. But it is worth reading the whole dissent. Harlan wrestled with his sense of perceived facts against his reading of the principles of the Constitution and, alone, came down on the side of principle. It removes nothing from his moral courage though, to gain insight by reading some of the perceived facts which are so far out of sympathy with our current views as to be shocking.

In respect of civil rights common to all citizens, the Constitution of the United States does not, I think, permit any public authority to know the race of those entitled to be protected in the enjoyment of such rights. Every true man has pride of race, and, under appropriate circumstances, when the rights of others, his equals before the law, are not to be affected, it is his privilege to express such pride and to take such action based upon it as to him seems proper. But I deny that any legislative body or judicial tribunal may have regard to the race of citizens when the civil rights of those citizens are involved. Indeed, such legislation as that here in question is inconsistent not only with that equality of rights which pertains to citizenship, National and State, but with the personal liberty enjoyed by everyone within the United States.

[snip]

But in view of the Constitution, in the eye of the law, there is in this country no superior, dominant, ruling class of citizens. There is no caste here. Our Constitution is color-blind, and neither knows nor tolerates classes among citizens. In respect of civil rights, all citizens are equal before the law. The humblest is the peer of the most powerful. The law regards man as man, and takes no account of his surroundings or of his color when his civil rights as guaranteed by the supreme law of the land are involved. It is therefore to be regretted that this high tribunal, the final expositor of the fundamental law of the land, has reached the conclusion that it is competent for a State to regulate the enjoyment by citizens of their civil rights solely upon the basis of race.

[snip]

The arbitrary separation of citizens on the basis of race while they are on a public highway is a badge of servitude wholly inconsistent with the civil freedom and the equality before the law established by the Constitution. It cannot be justified upon any legal grounds.