… You say it. McCain-Feingold said it. Individual shareholders in a corporation remained entirely free to make what ever contributions or videos were otherwise permitted by law, but corporations, when acting in their corporate capacity, had additional restrictions placed on them. Courts are well equipped to apply that distinction.
That’s consistent with a plausible and defensible reading of the First Amendment under which only natural persons have First Amendment rights, though like the reading the Court actually adopted, it leads to some unwanted consequences (like Planned Parenthood or the ACLU losing First Amendment rights). The question whether the thing can be done (which is the question I understand you to be asking) is separate from the question of which of the two readings represents the better policy (which is the question you appear to be folding into question 1 elsewhere).