Cutting off ACORN funding unconstitutional?

Politico floats the idea:

Article 1, Sections 9 and 10, of the Constitution explicitly prohibit the passage of “bills of attainder”: legislation targeted to benefit or penalize an individual or group, most often by excluding it from government service.

Does the House’s Defund ACORN Act, which passed 345-75 last week, constitute a bill of attainder? The case law on the issue is inconclusive, but it’s provided a glimmer for ACORN’s diminishing cadre of defenders.

Rep. Jerrold Nadler (D-N.Y.), chairman of the House Subcommittee on the Constitution, Civil Rights and Civil Liberties — and one of the 75 Democratic nays — made the case in a floor speech last Thursday, saying the bill was “done in the spirit of the moment, and nobody had the opportunity to point out that this is a flat violation of the Constitution.”

If I remember correctly, the same argument was made against the AIG executive bonuses when Congress tried to come up with a way to take the money back. That effort failed, largely due to it being unconstitutional.

However, I wouldn't expect for this to go anywhere.