Republican lawmakers are moving into open confrontation with the White House on everything from its conduct of the war on terrorism - at home and abroad - to its vision of American power.
It's a shift that reframes the final 35 months of a presidency that has counted on the Republican-controlled Congress to follow its lead, especially on issues of national security.
The GOP-controlled Congress has sparred with the White House before, on issues like spending restraint and Social Security reform. But since the Katrina debacle and, more recently, the Dubai ports deal, lawmakers on both sides of the aisle are taking on the president over what has been his strength: national security.
So far, most of the fireworks have been in the Senate, where lawmakers last week forced changes in the USA Patriot Act, blasted the Dubai ports deal - including calls for a congressional veto - and held a second hearing to help craft a new law to curb domestic spying without a warrant.
This week, the revolt spills into the House, where GOP leaders have traditionally given President Bush his most dependable support.
Monday, Rep. Duncan Hunter (R) of California, the chairman of the Armed Services Committee, will propose legislation that not only axes a Dubai firm's takeover of terminals at six American ports but also would require all foreign owners to divest management of US port facilities and other assets deemed critical to national security.
"We can't trust Dubai with our critical infrastructure," he says, citing reports that United Arab Emirates officials moved components of weapons systems through Dubai, including high-speed electrical switches to Pakistan, 70 tons of heavy water to India, and gas centrifuge parts to Iran. Neither the president nor congressional leaders have been adequately briefed on the matter, he adds.
Later in the week, the International Relations Committee is expected to begin tough hearings examining Mr. Bush's proposed US-India Civilian Nuclear Cooperation Agreement, which provides American assistance to India's nuclear power industry but does not require concessions on its nuclear weapons program.
It's a side deal that allows India to ramp up its production of weapons-grade plutonium, encouraging other nations to violate nonproliferation agreements at a critical time, congressional critics say. US law prohibits the sale of nuclear technology to any nation, such as India, which has not signed the Nuclear Non-Proliferation Treaty.
In a short statement, International Relations chairman Henry Hyde (R) of Illinois said that his committee will "thoroughly examine the specific provisions of this agreement and its potential consequences for US interests and those of the international community."
Like many of his colleagues, Chairman Hyde has been simmering over the priorities of foreign policy under the Bush administration. In an opening statement in hearings over the International Affairs budget request for FY 2007, he challenged whether the Bush administration's commitment to worldwide promotion of democracy makes sense without a commitment to "long-term presence of American power" that the nation can't afford.
"There is no evidence that we or anyone can guide from afar revolutions we have set in motion. We can more easily destabilize friends and others and give life to chaos and to avowed enemies than ensure outcomes in service of our interests and security," said Hyde, who is retiring.
Reps. Edward Markey (D) of Massachusetts and Fred Upton (R) of Michigan have already launched a coalition to oppose congressional approval of the nuclear deal with India.
"There is bipartisan opposition to this deal in the Congress, and when the full story is known it will be a bookend to the Dubai port deal - another case of the Bush administration announcing a commercial deal without due regard for its impact on national security interests," said Mr. Markey in a statement last week.
Most of the opposition on Capitol Hill is still focused on the Dubai ports deal, which caught members off guard during the last congressional break.
At the end of a closed briefing last Monday, Sen. Susan Collins (R) of Maine, the chairman of the Senate Homeland Security and Governmental Affairs Committee, said she was "more convinced than ever that the process was truly flawed." GOP senators are discussing whether to press for a vote on the deal.
But however strongly Republicans disagree with the Bush White House, they are also not eager to see the president slip still further in public opinion polls, especially in the runup to fall elections that could tip control back to Democrats.
"While Republicans are taking the president on more these days, they don't want him to fail," says Michael O'Hanlon, a senior fellow at the Brookings Institution. With most of the public attention focused on ports, the nuclear deal with India may yet squeak through the Congress.
"Improving relations with India gives the president a win when he's beleaguered at home," he says.