OK, if you really read Mr. Justice Kennedy's opinion for the Supreme Court's majority in the Citizens United case, you just have to agree with his reasoning.
No one wants to limit free speech. It would be unconstitutional! The First Amendment is one of our proudest achievements.
So of course, if corporations are just like individual persons, they ought to enjoy exactly the same free speech rights as the rest of us do. No more, no less.
Right! But wait just a minim here folks. How did corporations get to be persons?
It seems sort of counter-intuitive. After all, corporations don't serve in the armed forces defending our country. They don't show up for jury duty. They don't marry and have kids and mortgages. They don't vote. In fact, come to think of it, they don't do almost all the things people do.
So how did they ever get to be people?
So I read the Constitution. And I couldn't find a word about corporations being people.
As a non-lawyer, I then figured there must be a bunch of legal eagles somewhere in the picture. Maybe one of those pesky activist judges.
So I looked.
What I learned from Wikipedia was that back in 1886, there was a case that went to the Supreme Court called Santa Clara County v. Southern Pacific Railroad Company. Before this case was argued, Supreme Court Justice Morrison Remick Waite simply pronounced, as follows:
The court does not wish to hear argument on the question whether the provision in the Fourteenth Amendment to the Constitution, which forbids a State to deny to any person within its jurisdiction the equal protection of the laws, applies to these corporations. We are all of opinion that it does.
Thus, Wikipedia tells me, "the doctrine of corporate personhood, which subsequently became a cornerstone of corporate law, was introduced into this 1886 decision without argument."
And then the court reporter duly entered into the summary record of the Court's findings that:
The defendant Corporations are persons within the intent of the clause in section 1 of the Fourteen Amendment to the Constitution of the United States, which forbids a State to deny to any person within its jurisdiction the equal protection of the laws.
Thus it was that a two-sentence assertion by a single judge elevated corporations to the status of persons under the law, prepared the way for the rise of global corporate rule, and thereby changed the course of history.
Since then, the Feds and many State governments have passed laws limiting the rights of these corporate "people" to express themselves. Clearly unconstitutional.