"Legally, our notion of the corporation is very much a product of the European High Middle Ages. The legal idea of a corporation as a "fictive person" (persona ficta) -- a person who, as Maitland, the great British legal historian, put it, "is immortal, who sues and is sued, who holds lands, has a seal of his own, who makes regulations for those natural persons of whom he is composed -- was first established in canon law by Pope Innocent IV in 1250 AD, and one of the first kinds of entities it applied to were monasteries -- as also to universities, churches, municipalities, and guilds.
The idea of the corporation as an angelic being is not mine, incidentally. I borrowed it from the great Medievalist Ernst Kantorowicz, who pointed out that all this was happening right around the same time that Thomas Aquinas was developing the notion that angels were really just the personification of Platonic Ideas. According to the teachings of Aquinas," he notes, "every angel represented a species."
Little wonder then that finally the personified collectives of the jurists, which were juristically immortal species, displayed all the features otherwise attributed to angels... The jurists themselves recognized that there was some similarity between their abstractions and the angelic beings. In this respect, it may be said that the political and legal world of thought of the later Middle Ages began to be populated by immaterial angelic bodies, large and small: they were invisible, ageless, sempiternal, immortal, and sometimes even ubiquitous; and they were endowed with a corpus intellectuale or mysticum [an intellectual or mystical body] which could stand any comparison with the "spiritual bodies" of celestial beings.
All this is worth emphasizing because while we are used to assuming that there's something natural or inevitable about the existence of corporations, in historical terms, they are actually strange, exotic creatures. No other great tradition came up with anything like it.
--David Graeber, Debt: The First 5,000 Years, p. 304.
I think that's how the Roberts Court see corporations -- as angels that are better than actual human beings. That's why the Roberts Court consistently grants rights to corporations that actually exceeds the rights they grant as natural to human being.