Talkin' 'bout my corporation

In a recent post about how "the American consensus" began to unravel with Goldwater, Digby quoted a Goldwater speech:

In order to achieve the widest possible distribution of political power, financial contributions to political campaigns should be made by individuals and individuals alone. I see no reason for labor unions—or corporations—to participate in politics. Both were created for economic purposes and their activities should be restricted accordingly.

This prompts me to finally post something that's been on my mind for a few months now: why not remove "personhood" from corporations, and perhaps from other groups and associations?

Right now, many of the things that companies can do are possible because they get treated as persons under the law. A company has things like privacy rights, political power, and legal standing because the courts treat it as a person. But what if we passed a law simply stating, in appropriate legalese, that "No law shall be construed as granting to a group or association any rights or status reserved to individual persons."?

It would probably have to be a Constitutional amendment, for all I know; and I'm sure there are a ton of complex considerations on both sides. Which groups or corporate bodies would this apply to—are there any for whom we would want to preserve personhood? And which rights or status—are there individual rights we would want to continue to extend to corporations?

What do you think? What are the pros and cons? Why should a corporation have a right to privacy, or a right to trial by jury, or the power of political donation?

(By the way, go read the entire Digby post, the thesis of which is, "There can be no doubt that Goldwater’s ideas are now mainstream.")