The Senate Judiciary Committee held hearings in early 2006 into whether or not President Bush and Attorney General Alberto Gonzales had the legal authority to sanction the program. Soon after, the Senate intelligence committee created a seven-member bipartisan subcommittee to conduct an investigation into the matter.
The program sidesteps the Foreign Intelligence Surveillance Act, which created a separate Foreign Intelligence Surveillance Court to approve all requests for electronic eavesdropping surveillance. Congress approved FISA in 1978 in response to revelations that President Nixon had illegally ordered wiretaps on domestic organizations without seeking a warrant.
Critics of the wiretapping program now argue that President Bush acted illegally and disrupted the established system of governmental "checks and balances" when he authorized the NSA to circumvent FISA.
In an interview on the NewsHour, Gonzales explained that the Authorization for Use of Military Force passed by Congress on Sept. 18, 2001, following the terrorist attacks on the United States, rendered moot the discussion over the legality of FISA.
"In the authorization to use military force Congress has told the president of the United States, you may engage in all the activities that are fundamentally incidental to waging war," Gonzales said.
Congressional authorization to use military force
The crux of the Bush administration's argument is that the Authorization for Use of Military Force allows wiretapping of suspected terrorists without FISA court approval.
In that statute, Congress authorized the president to "use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks."
Gonzales, who served as White House counsel at the time of the Sept. 11, 2001 attacks, believed along with other administration officials that this section of the Authorization for Use of Military Force overrides the FISA law.
In the legal defense submitted to the Senate Judiciary Committee, Gonzales cited a clause in FISA that prohibits law enforcement agencies from "engage[ing] ... in electronic surveillance under color of law except as authorized by statute." The Authorization for Use of Military Force, according to the attorney general, is such a statute.
"[E]lectronic surveillance conducted by the president pursuant to the AUMF ... is fully consistent with FISA," wrote Gonzales.
Sen. Patrick Leahy of Vermont, the ranking Democrat on the Judiciary Committee, however, told the NewsHour, "I want to make it very clear that the illegal spying on Americans is not authorized by the Congress or by any law whatsoever."
In an opinion piece published in The Washington Post on Dec. 23, 2005, Tom Daschle, who was Senate majority leader at the time the Authorization for Use of Military Force was passed, asserted that the Senate intentionally left out language that would have provided President Bush with a broad definition of executive power.
"I did not and never would have supported giving authority to the president for such wiretaps," wrote Daschle. "I am also confident that the 98 senators who voted in favor of authorization of force against al-Qaida did not believe that they were also voting for warrantless domestic surveillance."
The Hamdi case
Gonzales also said the Supreme Court gave the president the authority to order warrantless wiretaps in its Hamdi v. Rumsfeld decision. The court ruled that the Authorization for Use of Military Force gave the government the authority to detain Yaser Hamdi, a U.S. citizen deemed an "unlawful combatant."
On the NewsHour, Gonzales said that the plurality opinion in Hamdi argued that, "Detention of people captured on the battlefield is a fundamental incident of waging war." By extension, the National Security Agency wiretapping program is also a "fundamental incident" in the war against terror, according to the Bush administration.
But critics point to the opinion of Justice Sandra Day O'Connor, who argued that the Hamdi case does not apply to the wiretapping program, and wrote that "a state of war is not a blank check for the president."
"Sandra Day O'Connor made it very, very clear, even in a time of war the president is not above the law. None of us is above the law," Leahy said.
The Bush administration also has argued that apart from the Authorization for Use of Military Force, the Constitution gives the president inherent authority to approve warrantless wiretapping.
Article II of the Constitution establishes the president's authority as commander in chief of the armed forces. Gonzales told the Senate Judiciary Committee, "Under Article II, the president has the duty and the authority to protect America from attack. Article II also makes the president, in the words of the Supreme Court, 'the sole organ of government in the field of international relations.'"
Some senators on the Judiciary Committee voiced the concern of many critics of the NSA program that the Bush administration had violated the Fourth Amendment of the Constitution, which protects citizens from "unreasonable searches and seizures." The amendment requires that "probable cause, supported by oath or affirmation" be in place for a search warrant to be issued.
Gonzales said the NSA wiretapping did not fall under the "unreasonable" category because the federal government's responsibility to protect its citizens from foreign attack "outweighs the individual privacy interest at stake, and because [the NSA] seek[s] to intercept only international communications where one party is linked to al-Qaida or an affiliated terrorist organization."
In addition, the Bush administration has cited the actions of past presidents, all the way back to George Washington, as evidence of the longstanding necessity for executive authority during wartime. While commander in chief of the Continental Army in 1777, Washington wrote, "The necessity of procuring good intelligence is apparent and need not be further urged." He also allocated a special fund for the group that eventually became the Central Intelligence Agency.
More recently, the Bush administration argues, Franklin Delano Roosevelt ordered his attorney general to approve wiretaps for the "conversation or other communication of persons suspected of subversive activities against the government of the United States." And President Harry Truman approved a similar order while in office, citing reasons of national security. The unchecked practice continued until Congress passed the FISA law in 1978.