You can't bar speech for one of these for the reason of not being human, without risking the others. That would leave only the rich humans (e.g. George Soros) with the ability to widely broadcast their political beliefs.
The country would be better served if every individual had the same limitations put on their political contributions. Churches that are also 501C3 corporations already have limits set.
Why should people be taxed on their earnings while corporations be allowed to sit on piles of untaxed profits?