The suggestion that corporations shouldn't have free speech rights because they aren't people would be more compelling if the first amendment said something like "people have a right to free speech" instead of
Congress shall make no law ... abridging the freedom of speech ...
In this case, Congress has clearly made a law abridging the freedom of speech.
I seem not to have previously made explicit that the Court may have ruled more broadly than necessary in Citizens United. I stand by the assertion, though, that even people who oppose the general protection of corporate political speech and believe that it's not Constitutionally required are simply being dishonest if they look at the details of this particular case and claim that the plaintiffs shouldn't have won. Which leaves three current Justices dishonest.