I had counted unions under "organizations", but I should have realized that wouldn't be apparent to everyone. However, what is the fundamental difference between a corporation/business and a union? The former is a for profit private entity. The latter is a nonprofit organization dedicated to furthering worker's rights and interests. I understand what you're trying to (at least to my knowledge) do. Since unions are allowed to donate, why not corporations? Well, unions generally use the money given voluntarily by workers and employees to use for their political goals, as opposed to a corporation using its general funds to finance its own. A union is more of an extension of citizens donating their own money rather than by a few elite using corporate funds. That's the method of a plutocracy. I would further elaborate, but that's very time consuming.