“Inequality of rights is created by a combination in one part of the community to exclude another part from its rights. Whenever it be made an article of a constitution, or a law, that the right of voting, or of electing and being elected, shall appertain exclusively to persons possessing a certain quantity of property, be it little or much, it is a combination of the persons possessing that quantity to exclude those who do not possess the same quantity. It is investing themselves with powers as a self-created part of society, to the exclusion of the rest.”