Great piece from NPR
A corporation is not, nor has it ever been, a constitutional person with voting rights; it is not, not has it ever been, a democratic citizen; nor has it ever been a constituent member of "We the People " The founders did not mention the word "corporation" in the Declaration of Independence or the Constitution, and only a handful of corporations were even in existence at the time the Constitution was written.
The corporation is not a membership organization but an "artificial entity," as the Supreme Court has called it, chartered by the state or federal governments to serve public purposes. Legally speaking, it has no independent constitutional standing outside of the rights of the people who own it — and they already have the right as citizens to contribute and spend on campaigns. The idea now being promoted that CEOs have a First Amendment right to take other people's money out of corporate treasuries to spend on politics is outlandish.
Read it all.