From Charlie Savage -

But Mr. Obama also signaled that he intended to use signing statements himself if Congress sent him legislation with provisions he decided were unconstitutional.

Mr. Bush’s use of signing statements led to fierce controversy. He frequently used them to declare that provisions in the bills he was signing were unconstitutional constraints on executive power, and that the laws did not need to be enforced or obeyed as written. The laws he challenged included a ban on torture and requirements that Congress be given detailed reports about how the Justice Department was using the counterterrorism powers in the USA Patriot Act.

Since the 19th century, presidents have occasionally signed a bill while declaring that one or more provisions were unconstitutional. The practice became more frequent with the Reagan administration, but it initially drew little attention.

That changed under Mr. Bush, who broke all records, using signing statements to challenge about 1,200 sections of bills over his eight years in office, about twice the number challenged by all previous presidents combined, according to data compiled by Christopher Kelley, a political science professor at Miami University in Ohio.

Many of Mr. Bush’s challenges were based on an expansive view of the president’s power, as commander in chief, to take actions he believes necessary, regardless of what Congress says in legislation.

The American Bar Association declared that such signing statements were “contrary to the rule of law and our constitutional separation of powers,” and called on Mr. Bush and future presidents to stop using them and to return to a system of either signing a bill and then enforcing all of it, or vetoing the bill and giving Congress a chance to override that veto.

The Obama administration portrayed its approach as a major departure from that of Mr. Bush. But Senator Arlen Specter of Pennsylvania, the ranking Republican on the Senate Judiciary Committee, disagreed, saying Mr. Obama was “wrong” to embrace the view that signing statements can be constitutionally legitimate.

“I think the Constitution is explicit as to how you handle these situations, and if the president thinks something is unconstitutional, then he ought to veto it,” said Mr. Specter, an outspoken critic of Mr. Bush’s signing statements.

He called the practice a “dodge” and “a disregard for the separation of powers and co-equal branches of government.”