Re: Citizens United and Southern Pacific
If you dig a little deeper, you see that the sentence about how corporations are people and thus deserving of the rights normally accorded to a person was not part of the original decision, but was added by a clerk "cleaning up" for publication. Sort of like how "some staffer" made a 'typo fix" that resulted in the legal definition of "work for hire" changing from defaulting to the performer owning the copyright to the publisher owning it, in the absence of explicit wording in the contract. Thus effectively changing the terms of many contracts after they had been signed.
But of course these sort of "mistakes" would not have gotten through the courts and congress if they did not have support among the folks best placed to whisper in judicial or legislative ears.