Good cites there from Hamlet. It’s clear that the practice of the executive disregarding laws that restrict the constitutional prerogatives of the executive branch has a lot of precedent and history. But there’s clearly a question of scale and scope here. Bush has issued at least 750 of these signing statements, vastly more than any other president. Here’s an example quoted from the Boston Globe:
Dec. 30: When requested, scientific information ''prepared by government researchers and scientists shall be transmitted [to Congress] uncensored and without delay."
Bush’s signing statement: The president can tell researchers to withhold any information from Congress if he decides its disclosure could impair foreign relations, national security, or the workings of the executive branch.
This is really a reach here. The Constitution emphatically does not give the executive responsibility for “foreign relations, national security, or the workings of the executive branch.” To argue that it does is to argue for an elasticity in the Constitution that would stagger those liberal jurists accused of “legislating from the bench.”
For reference, here’s what the Constiution does say about the duties of the executive branch:
"The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any subject relating to the Duties of their respective Offices, and he shall have power to Grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment.
He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur; and he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law: but the Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments.
The President shall have power to fill up all Vacancies that may happen during the Recess of the Senate, by granting Commissions which shall expire at the End of their next Session.
He shall from time to time give to the Congress Information of the State of the Union, and recommend to their Consideration such Measures as he shall judge necessary and expedient; he may, on extraordinary Occasions, convene both Houses, or either of them, and in Case of Disagreement between them, with Respect to the Time of Adjournment, he may adjourn them to such Time as he shall think proper; he shall receive Ambassadors and other public Ministers;** he shall take Care that the Laws be faithfully executed** [bolding mine], and shall Commission all the Officers of the United States."
This is the totality of his responsibilities, except for his veto power and a couple of other minor things.