[actsasbuffoon]

The example given by Pai was a terrible one. Marsha Blackburn wasn't blocked from advertising a conservative message; she was blocked from committing dangerously unscrupulous libel. Her ad was demonstrably untrue, and was likely to cause some lunatic to hurt someone.

It's true that Rep Blackburn has the right to express her opinion, but libel has always been an exception to freedom of speech in this country. Twitter is under no obligation to accept money in order to help someone spread libel.