Bush attempts to destroy US Constitution
That's right, they want to bypass the Constitution completely, and be able to put anyone, including citizens, in prison forever with no access to the current legal system.
That this bill violates multiple sections of the US Constitution does not, of course, matter or appear to be of much concern to the Bush and the neocons.
My take: Everything is going wrong for them; all the wars(s) are going badly, their poll numbers are abysmal, the Democrats, clueless as they are, could retake the House in November. So, they're getting desperate. This is a ploy to enrage their right flank into voting in November since Democrats, one hopes, will oppose it. Realistically, it has little chance of passing but does show how thuggishly amoral the neocons are.
It would be a logical next
It would be a logical next step, essentially rendering the US Constitution null and void. The executive could do anything it liked with any individual, simply by declaring (no proof required) that he or she is suspected of terrorism. It would be interesting to see if half of all American citizens would still stand behind such a measure, as they have supported pretty much all the rest of Dubya's moves.