Since 9/11, the Bush White House has moved aggressively to expand presidential power in wartime, at the expense of Congress. Until recently, the Republican-controlled Congress went along.
Even bipartisan concern that Samuel Alito would too enthusiastically support broad presidential powers was not enough to block his confirmation to the Supreme Court Tuesday.
But that deference may be ending. The Senate, especially, is gearing up to make the case that power between the executive and legislative branches is unbalanced.
Next week, the Senate begins the first hearings on the president's authorization of eavesdropping without a warrant.
At the same time, Republicans are divided over whether to extend 16 provisions of the USA Patriot Act that are set to expire this Friday. Four Senate Republicans are joining most Democrats to demand more protections for civil liberties.
"The presidency, whoever is in it, has real advantages in the struggle, but we may see that the Congress finally believes that the Bush administration has gone too far," says John Samples, director of the Center for Representative Government at the CATO Institute, a libertarian think tank.
For Sen. Arlen Specter (R) of Pennsylvania, who chairs the Judiciary panel, the two issues of NSA wiretaps and renewal of the Patriot Act are forever linked in time. The first reports of illegal domestic eavesdropping by the National Security Administration (NSA), published in The New York Times on Dec. 16, just before a key vote on the Patriot Act, "hit me like a cannonball between the eyes," he says.
He is asking Attorney General Alberto Gonzales to prepare for a full day of questioning on Feb. 6. Senator Specter wants to hear Mr. Gonzales explain why the Bush administration did not ask Congress to expand executive powers under the Foreign Intelligence Surveillance Act (FISA), if they were not adequate to protect the country.
"Was it because you thought you couldn't get such an expansion?" the chairman asked Gonzales in a Jan. 24 letter.
Congress, Specter wrote, was "predisposed" to grant the executive additional powers necessary to keep the nation safe. Why, then, not ask for them, or at least use the 72-hour "after-the-fact" authorization provided in the 1978 FISA? he asked.
The issue is looming so large that the White House devoted a full week in the run-up to this week's State of the Union Address to defuse the issue. Instead of "domestic spying" - the term used most often in the press - the White House described the program as "terrorist surveillance." Recent communication from Osama bin Laden and his Al Qaeda deputy, Ayman al-Zawahiri, appeared to reinforce the threat.
"The political outcome of this battle will depend on who succeeds in defining the terms of the debate," says Thomas Mann, a senior fellow at the Brookings Institution.
"If it's a straight tradeoff between security and privacy or liberty, security wins. If it's framed as a way of monitoring suspicious characters, it wins overwhelmingly," he says. "But if there is any hint of abuse of power or of the president not telling the truth, of scrutinizing citizens with no evidence of suspicious behavior, then it turns into something else."
If it were just a partisan fight, the White House charge that Democrats are locked in pre-9/11 mentality might carry the day. But four of the 46 senators who blocked a December vote to extend the Patriot Act are Republicans.
Pushback from both sides of the aisle over the president's conduct of the war in Iraq began after controversy over the treatment of detainees at Abu Ghraib prison. Congress responded with an amendment on the FY 2006 Defense Authorization bill - over an initial White House veto threat - that banned the torture of detainees. In a Dec. 15 White House meeting, the president thanked Sens. John Warner of Virginia and John McCain of Arizona, chief sponsors of the amendment, for their "good work on behalf of America."
But in a signing statement two weeks later, the president appeared to carve out a zone of discretion relating to detainees, consistent with "the constitutional authority of the president to supervise the unitary executive branch." The statement alarmed lawmakers on both sides of the aisle, who saw the move as a bid to thwart the intent of the law.
"President Bush continues to believe he's above the law and above the Constitution ... [that the] unitary executive president can pick and choose which laws he will follow," says Senate Democratic leader Harry Reid.
For Sen. Lindsay Graham (R) of South Carolina, who has also consistently challenged the White House on treatment of detainees, excessive claims of executive power could undermine the powers of future presidents, especially during war.
If the president carries the day with his claims that Congress's approval of a use-of-force resolution after 9/11 gave the White House the power to bypass legislation governing national security wiretaps, "the next president will have great difficulty getting a force resolution. Republicans will have diminished the power for future presidents," he says.
For some Republicans, the standoff over executive power recalls the fireworks between the Democrat-controlled Congress and the Reagan White House over the Iran-contra affair in 1987. The ranking Republican on the House Select Committee to Investigate Covert Arms Transactions with Iran was then Rep. Dick Cheney of Wyoming.
"There was no constitutional crisis, no systematic disrespect for 'the rule of law.... No one in the government was acting out of corrupt motives," concluded Republicans in their minority report.
It's an argument some Republicans plan to raise next week. "The president has inherent powers that Congress cannot take away," says Sen. Orrin Hatch (R) of Utah.