The slide to corporations having the same protected Constitutional rights as individuals began long before Citizens United and long before the off-hand, sidebar comment in Santa Fe Rail Road became the SCOTUS precedent for corporations as individuals.
Do a bit of history on the law of persona ficta as it pertains to admiralty law and then to commerce, and the lines are very clear as to how and why we got to where we are with corporations.
GG, you may not like it, but the legal history for it is very long and very plain. It's good law, and it's Constitutional. When you further figure that corporations and corporate law govern all non-profits, unions, associations, etc., that are represented as fictional persons and their own entities in contracts, disputes, cases, property ownership, etc., the line can't be drawn to divide one from another in regards to speech and pass Constitutional muster. At least, no more so than any line could be drawn between men of different skin tones or religious beliefs, and that clearly is unconstitutional.
As for Stevens veracity and any treatise on that, it'd be quite short: he has none, therefore there is none.
