Something I have not heard posited is the money trail. Presumably most people who knew of Enron's imminent demise sold a great deal of their stock.

So:

It is logical to think that Bush, et al, in appreciation of financial campaign support over the years, bought stock in Enron. (Isn't that what we would do?) OK- does Bush still hold Enron stock? Or did he sell his stock during this last year? Even if his assets have been put in a trust for the duration of his presidential years, it should be possible to ascertain the dealings.

The same thing holds true for other officials. People who sold off a lot of Enron stock last year could have some questions to answer.