Floyd Abrams has written a masterful exposition of the Citizens United decision. It is a classical repetition of the fallacy of Xeno's Paradox which had the hare never catching the tortoise. One can justify anything by starting with a faulty assumption.
He justifies the decision on the basis of the 1st Amendment. The 1st amendment refers to freedom of speech of "the people". Corporations are not people anymore than is a robot performing human feats. Corporate personhood is a legal fiction that emerged from an interpretation of a court's deliberation that never examined or even considered corporate personhood.
I am impressed only with his craftsmanship.
Richard C. Bozian M.D. F.A.C.P.
Professor Emeritus of Medicne
University of Cincinnati.