That is the underlying question that lawmakers and legal scholars are grappling with as they attempt to address President Bushs stated justification for authorizing the National Security Agency to eavesdrop on people in the United States without first obtaining a court order.
Those who say the president acted illegally argue that spying on Americans in the United States without a warrant violates the Foreign Intelligence Surveillance Act of 1978, which governs the way that electronic surveillance and domestic wire interception can be conducted.
Those who say the president acted legally argue that FISA is trumped by the inherent executive powers under Article II of the Constitution combined with Congress passage of the Authorization for the Use of Military Force on Sept. 14, 2001.
According to many of the NSA programs defenders, the battlefield in the war on terror includes the United States, where contemporary technologies, such as cell phones and the Internet, enable the enemy to move so fast that the government doesnt have time to comply with the warrant mandates under FISA.
However, the complications for law enforcement caused by rapidly evolving communications technologies entered into the debate on Capitol Hill nearly two decades ago.
With the growing popularity of wireless services in the early 1990s, the FBI sought to expand the amount of information it could collect from wiretaps.
E-mail, and then VOIP (voice over IP), created new ways for people to communicate outside of the public switched telephone network, where surveillance was customarily conducted within legal restraints.
After the Sept. 11, 2001, terrorist attacks, Congress gave the FBI some of the beefed-up powers they had been seeking, including the power to conduct "roving wiretaps," essentially tracking a targets movement.
These and other expanded powers were subjected to heated debate as Congress negotiated the reauthorization of the USA Patriot Act over the last six months.
For the NSA programs defenders, however, the communications technologies are moving faster than Congress.
Testifying before the Senate Judiciary Committee on Feb. 28, James Woolsey, vice president of the Global Strategic Security Division at Booz Allen Hamilton, said that contemporary "electronic battlefield mapping" does not fit into the laws warrant requirements.
"This is a fast operating world, this business of electronic battlefield electronic surveillance," Woolsey said.
"We are in the gun sights of more than one international terrorist Islamist organization."
Woolsey has the backing of some legal scholars who say that the war on terror is a novel war that requires new approaches.
Doug Kmiec, a professor at Pepperdine University School of Law, told the senators that the government needs a "programmatic way to have a detached set of eyes," which is not consistent with the FISA requirements.
Other legal scholars disagree. Harold Koh, dean of the Yale Law School, warned the committee that this argument would deem every search the government chooses to do "reasonable," obviating the Fourth Amendments protections altogether.
Under FISA, the president has the ability to sidestep the Fourth Amendment and authorize eavesdropping in the United States before getting a court order, but an order from the FISA court must be requested within 72 hours.
Also, the FISA allows the U.S. attorney general to approve warrantless surveillance in the United States for 15 days after a declaration of war, to pursue emergency situations while giving Congress time to pass whatever new laws are needed.
"The FISA was enacted by Congress precisely to regulate the kind of surveillance that has occurred here," Koh told members of Congress.
"In response, the Justice Department asserts that the president may choose clandestinely to ignore the FISA."
Kohs argument resonated with some senators.
"If, as [administration officials] claim, they can ignore FISAs express prohibition of warrantless wiretapping, can they also eavesdrop on purely domestic phone calls?" said Sen. Patrick Leahy, D-Vt.
"Can they search or electronically bug an Americans home or office? Can they comb through Americans medical records and open first-class mail?"
In other words, are there any limits to the presidents powers if federal laws can be ignored in todays war environment?
If there are no limits, what is the purpose of Congress?
"Taken seriously, the presidents reading of the Constitution would render Congress a pointless rubberstamp, limited in an unending war on terror to enacting laws that the president can ignore at will and issuing blank checks that the president can redefine at will," Koh told the committee.