Reply #10: Well, there's one pretty important one.

[SteppingRazor]

That being, the question of whether the Congress' constitutional ability to "determine the rules of its proceedings" (Art. I, Sec. 5, Cl. 2, as you alluded to) includes the ability of the President of the Senate (Cheney) or the President Pro Tem (at the time, Ted Stevens) to unilaterally declare a Senate rule to be unconstitutional and thus null and void. One of the two would have to do that, recinding Senate Rule 22 (which necessitates a two-thirds majority for a Senate rule change rather than a simple majority) without a required vote.

Each body of Congress is constitutionally liable for determining its own rules. At the same time, only the courts have the power of judicial review. Therein lies the gray area that could open up a court case.

Of course, on the other hand, I don't know that any court, includng the SCOTUS, would want to touch this with a 10-foot pole.