“The price you must pay for the enjoyment of your own liberty is the recognition that other people, especially people with whom you may not like to identify, have an equal claim to the same liberty. America requires an allegiance to the stern principle of liberty. This is the reason gay rights matter to Americans generally and not just to lesbians and gay men. Liberty, unlike nationality, cannot be safely restricted. Restriction turns liberty into privilege, and no American's freedom is safe if individual liberty changes from a right rooted in nature to a privilege rooted in custom.”