Certain Dems have been actively looking for a reason to impeach Bush since his first inauguration. Actually, since the Bush v. Gore decision was announced on 12/12/00. If the Dems win Congress back, they WILL at least attempt to impeach the President.
Gonzales' answer was that, if so, the determination of the constitutionality of any given surveillance becomes more difficult. Duh. That's the nub of the hearing.
I heard Carter blandly tell Larry King that "We won the 2000 election."