As for the others, who may or may not be relevant to impeachable offenses, Congress has full power to immunize them and hear their testimony in secret session. No law is necessary.
Without the Democrats in control in the past, we HAVEN'T heard these people yet. That's what I want to hear first to get the full extent, and therefore maximize the chance of getting conviction and maximize the punishment and the numbers of those being punished too. This isn't just Bush and Cheney. It is a whole conspiracy that needs to be brought down. We need to assemble as much evidence as we can to get rid of all of them!
For others that have been "silenced" because they are "State Secrets" silenced like Sibel Edmonds, Russell Tice, etc. since they have been singled out to not have whistleblower protection by previous legislation, haven't been able to tell us yet what they know. There's a REASON why the Republicans excluded them from protection, and I believe that is because they know things that will put the screws in those in this conspiracy. We need to get them out in the open.
In "Case for Impeachment" on page 9, they quote John Dean as follows:
"Impeachment is the most serious constitutional charge you can make against a federal official," he says, "and only an irresponsible judiciary committee would take up charges that could not be proven in a Senate trial. Only an irresponsible House of Representatives would pass a bill of impeachment that could not succeed in the Senate." For precisely that reason, Dean considers, the Cilnton impeachment to have been improper and irresponsible.
Looking for more points of the authors' opinions themselves, but I'll need more time to do that later. With my earlier comment on Chief Justice Roberts presiding, I think it's important to note the following section on page 47:
At the trial, the Senate sits as a jury with the chief justice presiding, ruling on all questions of evidence. Unlike the situation in a normal court of law, however, the Senate can reverse a ruling made by the presiding officer by a majority vote.
This makes it essential that ALL Democrats be on board with the proper strategy before bringing it to the Senate to have this majority (including keeping our Joe Lieberman happy, who will be heavily powerful in this instance). Otherwise, Roberts I'm sure will play all sorts of games to prevent this trial from happening or putting out any sort of constructive presentations of evidence. We need to be WELL prepared before we take this to the Senate.