There's no constitutional reason that the bill of rights should extend automatically to corporations (nor to robots or inanimate objects, for that matter). I'd be suspicious of any court using a first amendment argument to protect corporate interests.
If I have free speech rights, and if you have free speech rights, why should we not have free speech rights if we form a corporation and speak with one (amplified) voice?
Do you also believe that non-profits and churches should be able to freely lobby? Currently both are severely curtailed in their political speech, unlike for-profit corporations. This is why there are two ACLU organizations: http://www.aclu.org/american-civil-liberties-union-and-aclu-...
