It used to be that law and order was a conservative principle. With the Bush administration, the abiding principle is simply order. For this president, the law is passed off as anything he says it is.

Mr. Bush's exaggerated sense of executive power has posed a threat to the Constitution he has sworn to uphold. A study released last week by the Government Accountability Office provides more evidence to support this view.

One of the ways used to justify avoiding the letter of the law has been the presidential signing statement attached to legislation passed by Congress. Signing statements are not new -- they date back to the early years of the republic. Although they are not mentioned in the Constitution, they have been used by many presidents, including Jimmy Carter, Ronald Reagan, George H.W. Bush and Bill Clinton.

But they can be abused if they are applied not to extol a piece of legislation but to justify ignoring some of its provisions ostensibly because of constitutional or national security concerns. In his frequent use of signing statements, Mr. Bush gives the impression of inviting an activist judge of conservative stripe in some future case to ignore the intent of Congress and be swayed instead by the intent of the president.

Mr. Bush has used signing statements more than any other president before him, indeed all previous presidents combined, and his preference for them prompted the American Bar Association last year to convene a task force to study the question. Although the ABA task force report was careful not to criticize Mr. Bush, it did sound a warning against repeated use of signing statements in ways that are "contrary to the rule of law and our constitutional system of government."

The GAO report, which was requested by two Democratic lawmakers, Sen. Robert C. Byrd of West Virginia and Rep. John Conyers of Michigan, was limited in its scope, but its findings indeed suggest that the rule of law was subverted. The watchdog agency found that in six of 19 provisions in spending bills in fiscal year 2006, the law was not followed after President Bush expressed reservations about them in signing statements. The GAO report did not attempt to judge the constitutional merits of Mr. Bush's objections.

As The New York Times reported, lawmakers intend to look further into Mr. Bush's heavy use of signing statements. No doubt this will be dismissed as the usual partisan gamesmanship, but conservative Republicans true to their old principles ought to be as disturbed as Democrats. The president can always veto a bill he doesn't like, but he can't -- shouldn't -- change laws with the stroke of a pen.