WASHINGTON - The White House is bracing for guerrilla warfare on the homefront politically if Republicans lose control of the House, the Senate or both - and with it, the president's ability to shape and dominate the national agenda.
Republicans are battling to keep control of Congress. But polls and analysts in both parties increasingly suggest Democrats will capture the House and possibly the Senate on Election Day Nov. 7.
Democrats need a 15-seat pickup to regain the House and a gain of six seats to claim the Senate.
Everything could change overnight for President Bush, who has governed for most of the past six years with a Republican Congress and with little support from Democrats.
"Every session you change the way you do business with the Congress. And you test the mood of the Congress, find out what their appetite will be. But it doesn't change your priorities," the president told ABC News.
Former President Clinton had to deal with the Democrats' loss of control of Congress in 1994. But Clinton had something Bush does not: six more years to regain his footing.
Bush has barely over two years left. The loss of either house in voting next month could hasten Bush's descent into a lame-duck presidency.
"If he loses one house here, President Bush will enter the last two years very wounded," said David Gergen, a former White House adviser who served in the administrations of Presidents Nixon, Ford, Reagan and Clinton.
"He will have the capacity to say no to Democratic legislation, but he won't have the capacity to say yes to his own legislation," said Gergen, who teaches at Harvard University's Kennedy School of Government.
Democratic victories essentially could block Bush's remaining agenda and usher in a period of intense partisan bickering over nearly every measure to come before Congress.
Loss of either chamber also could subject his administration to endless congressional inquiries and investigations.
The president and chief political strategist Karl Rove last week expressed renewed confidence of retaining both House and Senate; others are not so upbeat.
"All of our numbers look pretty bad and there's no question that there's a jet stream in our face," said House Majority Leader John Boehner, R-Ohio.
Furthermore, some of Bush's fighting in the trenches is likely to be with fellow Republicans as they seek to find a new standard bearer for 2008 - and distance themselves from an unpopular war, the unpopular president who waged it, and congressional scandals that include inappropriate e-mails to House pages from ex-Rep. Mark Foley, R-Fla.
"There's no question that the Republican coalition is stressed over the way Washington has been handling fiscal matters, the Foley affair, the Iraq war," said GOP consultant Scott Reed. "All of these are coming together at the same time."
Already, Republicans are showing divisions on Iraq policy. Fresh skepticism has come from Senate Armed Services Chairman John Warner of Virginia, Texas Sen. Kay Bailey Hutchison and former Secretary of State James A. Baker III, a longtime Bush family loyalist.
If Republicans lose their majorities, it will be that much harder for Bush to hold together already splintering GOP cohesion on Iraq.
Bush has been quoted by journalist Bob Woodward as saying, "I'll stay in Iraq even if the only support I have left is from my wife and my dog." A Democratic takeover and Republican defections could make that day seem closer.
While the Senate has been difficult for Bush, even with GOP control, the House for most of his presidency has delivered for him. That could be about to change.
The White House traditionally loses seats in midterm congressional races. The most recent exception was 2002, when Bush's party picked up seats.
Many Democrats see the upcoming elections as a mirror image of 1994, with the parties reversed.
Then, Republicans rallied behind firebrand Rep. Newt Gingrich of Georgia, announced a "Contract with America," and stormed to victory, seizing both House and Senate from Democrats.
It was a huge blow to Clinton, made worse by the lavish and almost-presidential reception Gingrich received around Washington as he was inaugurated as House speaker.
Doug Schoen, Clinton's pollster then, said those times were bleak, including Clinton's baleful insistence to reporters in early 1995 that "the president is relevant."
But Clinton soon figured out how to enhance his relevance and influence, reaching out to Republicans on some of their own issues, such as welfare law overhaul and "talking about the common good," said Schoen. Clinton went on to easily win re-election in 1996.
But Schoen said he doubts Bush can do the same: "After 9-11, except for a brief period, he's governed from the right. There's so much bitterness and division, it's going to be tougher for him to do it than perhaps it was for Clinton."
Some of Bush's sharpest critics would rise to top positions with a Democratic takeover.
House Minority Leader Nancy Pelosi, D-Calif., probably would become speaker. Rep. Charles Rangel, D-N.Y., a foe of extending Bush tax cuts, would become chairman of the tax-writing House Ways and Means Committee.
Rep. John Conyers of Michigan, who has sponsored legislation calling for steps that could open the way to Bush's impeachment, would lead the Judiciary Committee.
If Democrats win the Senate, Democratic leader Harry Reid of Nevada - one of the most outspoken of all Bush critics - probably would ascend to majority leader.
The Republican Party chairman, Ken Mehlman, even raises the specter of a leadership troika of Pelosi, Reid and Democratic party chief Howard Dean, in GOP fundraising mailings to Republicans.
Bush, in his own get-out-the-vote appeal, told Republicans: "The consequences of not succeeding this fall are dire for our agenda for America."
Bush even suggested last week that insurgents in Iraq were stepping up their violence in a bid to influence the elections.
Polls in 2006 show a more dramatic tilt toward the Democrats than polling in 1994 showed a tilt toward Republicans. But redistricting has made far fewer congressional districts competitive.
A Democratic takeover of one or more chambers would all but guarantee that Bush would not get his Social Security overhaul or further tax cuts through Congress.
One Bush initiative that actually might see improved chances is his immigration proposal for a "guest worker" program. That actually has more Democratic than Republican support.
Stephen Wayne, a professor of government at Georgetown University, said a loss of House or Senate would cripple Bush domestically - but might actually give him more room to find a way out of Iraq.
"Were he to choose to moderate the course in Iraq, the Democrats would say, `I told you so' and the Republicans would say, `Thank you,'" said Wayne.