(1) The Congress has the right to restrict the President's eavesdropping activities, and to make certain eavesdropping activities a criminal offense punishable by up to five years in prison.
(2) Therefore, Hatch votes several times for FISA.
(3) Every President since then complies with the law -- including President Reagan and Bush 41 during the height of the Cold War - and no Administration or member of Congress challenge its constitutionality.
(4) George Bush gets caught violating FISA by engaging in the precise eavesdropping which FISA criminalizes.
(5) Hatch says that the Leader did nothing wrong because the law which the Leader violated -- the same one Hatch voted to enact and to amend repeatedly -- is unconstitutional.
I trust that clears it up for you. If Bush violates a law, then by definition it becomes unconstitutional.