The SCOTUS ruling in the 'Citizens United' only established that because you work for a corporation you do not lose your rights to free speech. That's it. If the government had the right to regulate the speech of people that belong to corporations they would have the same rights to control the speech of people that belong to unions, political parties, or protest groups or any other such organization.
The claim that the 'supreme court ruled corporation is a person' misrepresentation of the worst kind and was done purely for propaganda purposes. It really needs to go away.
Personally I think the Citizens United ruling was a good thing, because the campaign finance system was hopelessly broken. It was another case of good intentions, but bad results in the real world. Anyone with enough money could easily abuse the system; only the small grassroots guys might run afoul of it. So kind of like the patent system-- great in theory, terrible in practice.