A commercial or advertisement is defined as something that "poses nothing more than a commercial transaction." E.g. "Buy this iPad it's great!"

There is no way to shoe-horn "Hilary: The Movie" into the "just a commercial" mold. Here are a list of other movies produced by Citizens United: "ACLU: At War with America" (this one is ironic); "Broken Promises: The UN at 60"; "Rediscovering God in America." Now, you might not like the organization's political message, but I don't see a principled way to distinguish them from some of my Sierra Club favorites like "Coal Country" and "Oil on Ice."

What is "paid speech" even supposed to mean? What movies don't cost money to make? Or for that matter books or pamphlets or newspapers? Both Citizens United and the Sierra Club are not-for-profit corporations. They are created for the express purpose of getting out a particular message, and that costs money. Their message should not be taken out of the protection of the First Amendment just because of that fact.

It should be noted that Grand Theft Auto not only cost money, but it was a for-profit product...

It's not about money, it's about the paper trail. Who's responsible? Who is spending the money? Who is donating the money?

These are basic things that need to be made obvious.

Buy all the ads you want, it's fine with me. As long as I know you are the one buying the ads.

The right to anonymous speech is something we hold pretty dear here in the US. It goes back all the way to the anonymous publishing of the Federalist Papers.

Who cares who bought the ads? Do you use that as a basis for evaluating their truth?

In the case of corporate sponsored speech? You bet I do. And "truth" isn't the problem so much as bias. You can state the exact same true fact 50 different ways and spin it to mean almost anything you want.

I've looked all through the First Amendment, and I don't see any exceptions for "paid speech." Help me out?

Commercial speech has to do with the content of the speech, not the motivations behind speaking.

If I have a statement: "hats are on sale 50% off tomorrow" that is commercial speech. I can tell on it's face that it's commercial, without knowing anything about who spoke it.

If I have a statement: "Hilary Clinton is a terrible candidate for such and such reasons" that is not commercial speech. It does not, on it's face, propose a commercial transaction. Now, someone might have commercial reasons for disliking Hilary Clinton, but the motivation behind speech is irrelevant to whether it is considered to be within the "commercial speech" exception.

This is why music, movies, and video games are all fully protected despite the fact that they are for-profit commerical products. It's the content of the speech, not the motivations for speaking that define speech as commercial or not.

So your local politicians raise their right hand and swear to uphold Wikipedia? I can see some room for abuse there.