1. I'm a business student. I'm founding a company. I'm not opposed to corporations either. Just their involvement in politics.
2. Michael Moore and Sean Penn are individuals, not corporations. I support the right of the Koch brothers to speak out, though I don't much like what they have to say. I don't support the right of their corporation to pay to be heard on political matters.
3. It's paid advertising that I'm opposed to; corporations can make documentaries all day long if they want to, it's paying to have people watch them that I have a problem with.
4. Newspapers can blatantly support political parties and candidates. People choose to read them if they wish; they don't find them embedded in other content as paid advertising.
EDIT: in response to the below, see my post above (GP).