I don't think that we have had a great deal of information on this story yet. But, on the face, it sounds horrific. If Bush is found to have authorized illegal survalience of american citizens, I would be infavor of impeaching him.

In illegal wire tap is no different than an illegal search and seizure.
From the Bill of Rights

"Amendment IV

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."