The Legality Of Nationalization

I've cited this issue a few times, because many I trust have told me it's relevant. Ezra does some reporting:

"Many of the critics," one official sighed to me, "are underestimating the difficulty of their counterfactuals." Ben Bernanke does not appear to think the administration has the legal authority to forcibly take investment banks into receivership. What happens if a legal challenge disrupts the process?

Virtually no one thinks that Congress is willing to quickly offer either the legislation authorizing such an action nor the massive upfront money that receivership would require. Will Ben Nelson and George Voinovich vote to take control of the banks? And what happens to the market while Congress is debating? And to Congress if the market dives?