Our progress in degeneracy appears to me to be pretty rapid. As a nation, we began by declaring that “all men are created equal.” We now practically read it, “all men are created equal except negroes.” When the Know-nothings get control, it will read, “all men are created equal except negroes and foreigners and Catholics.” When it comes to this, I shall prefer emigrating to some country where they make no pretense of loving liberty—to Russia, for instance, where despotism can be taken pure, and without the base alloy of hypocrisy. / Abraham Lincoln
What did Lincoln mean by saying "without the base alloy of hypocracy"?