Here’s a great column from Glenn Greenwald:
Events like this provide an important reminder about how crucial and well-crafted the Constitution is. Though rarely invoked, the ban on “bills of attainder” is no technical or legalistic right; it’s vital. Allowing Congress — rather than courts — to pass judgment on parties’ guilt and then punish them for it is to circumvent all of the due process rights guaranteed in a judicial proceeding. It virtually ensures that, as happened here, guilt will be imposed due to political passions and a lynch mob mentality rather than a careful and fair examination of evidence. It also leaves weak and unpopular parties far more vulnerable to punishment. The fact that groups far more powerful than ACORN have actually been found guilty of serious wrongdoing yet have never been de-funded by Congress –particularly defense contractors — illustrates that danger.
The reasons the Founders barred such bills of attainder are perfectly highlighted by the ACORN case. During the reign of abusive Kings, it was a favorite instrument for enabling unpopular parties to be convicted, punished and deprived without benefit of a trial. Under the Constitution, parties aren’t supposed to be found guilty of wrongdoing as a result of a Fox-News-led witch hunt joined by cowardly members of Congress. The recent finding of the Massachusetts Attorney General that ACORN had not committed crimes in connection with the notorious prostitution videos underscores the danger of the state’s assuming someone’s guilt outside of the judicial process. Congress is especially ill-suited to pass judgment on whether a particular party has violated the law, as they are far more likely to protect the powerful and popular and punish the weak and unpopular (which is one reason, incidentally, why it was wrong for Congress to retroactively immunize rich and powerful telecoms based on the consummately judicial finding that they acted in “good faith” when violating eavesdropping laws).
I highly recommend reading the whole thing.