WASHINGTON — Republicans' raucous rebellion against the White House on a port management deal has proved to be a crucial juncture in George W. Bush's presidency, signaling how dramatically his vise-like grip on the GOP has been loosened in his second term.
It also serves to underscore a fundamental political reality: Most Republicans in Congress are up for reelection in 2006, and Bush is not.
For the first time, Bush is facing pointed, emotional opposition across the GOP political spectrum. From senior leaders to backbenchers, congressional Republicans are showing a rare willingness to go public with their criticism of his administration's decision to allow an Arab company to manage terminals at several large U.S. ports -- a remarkable development for a White House notoriously intolerant of dissent.
A key question is whether the port imbroglio is an episode that will pass without lasting political effect or whether it will permanently damage Bush's position in the party, especially among the conservative base that sparked the opposition to the deal.
Panicked lawmakers fear that Bush, with no reelection bid facing him, was insensitive to the port decision's political risks and that Democrats now have an election-year opportunity to portray themselves as tougher in fighting terrorism than the president and his allies.
"His political antennae are totally different right now," said Rep. Mark Souder (R-Ind.). House Republicans, he continued, have given Bush this message in private meetings: "You've developed a tin ear. You're not running, and you don't understand what we are hearing at the grass roots."
But if Bush alienates conservatives with his stands on port management, immigration and other hot-button issues, some analysts say that in the 2006 midterm elections, he may not be the unalloyed political asset he was in past campaigns.
"I don't think he will be a liability, but his potency to go in and campaign for a candidate may be significantly eroded," conservative activist Paul M. Weyrich said.
For now, Bush remains popular among Republican voters. He is still in demand as a fundraiser and campaigner; on Thursday, he attended political events for two Republicans, Rep. Chris Chocola of Indiana and Sen. Mike DeWine of Ohio.
"If the members on the ground thought the president was a burden, they wouldn't be welcoming him to their district, but they are proud to stand with him," White House spokesman Trent Duffy said.
The GOP reaction to the port decision may also represent the starting gun for the race among Republicans to succeed Bush in 2008. One of the leading critics was Senate Majority Leader Bill Frist of Tennessee, usually a stalwart ally, who might need to distance himself from Bush to mount a presidential campaign.
One of the few senior Republicans who stood by Bush was Sen. John McCain of Arizona, a staunch critic at times who is trying to strengthen ties to the president's allies as he prepares for a possible White House race.
"We're in a period in which all eyes have moved away from Bush," said Charles O. Jones, professor emeritus of political science at the University of Wisconsin-Madison. "Having a term limitation is an invitation for turning your eyes from what was to what is likely to be in the future."
Some Republicans contend that the port controversy will prove to be a blip on the political screen, a flare-up that will die down as lawmakers learn more about the issue. The White House formally began that process Thursday by holding an open briefing on the deal for the Senate Armed Services Committee.
"This is just a screw-up," said GOP pollster Whit Ayres. "I think the base will, after some initial bluster, give him the benefit of the doubt, once they have the facts."
It is the latest in a series of episodes in which congressional Republicans have been uncharacteristically willing to challenge the White House, eroding the iron-clad party discipline that was a cornerstone of Bush's first-term accomplishments.
In recent months, members of both parties have criticized Bush's domestic surveillance program. A House committee has issued a scathing report on the administration's handling of Hurricane Katrina. In December, Bush signed a bill containing a measure that he had fought for months, formally banning torture of detainees in U.S. custody anywhere in the world. It has been a marked change in tone from Bush's first term when, for the most part, the White House and the Republican majority on Capitol Hill operated more like a team than at any time in recent memory.
Congress has been especially deferential to Bush on national security -- and followed his lead on domestic policy as well, even on education and Medicare initiatives that conservatives loathed. Bills have been written near enough to Bush's liking that he has never cast a veto.