Analysts in both parties say all major indicators tilt toward the Republicans. President Barack Obama's policies are widely unpopular. Congress, run by the Democrats, rates even lower. Fear and anger over unemployment and deep deficits are energizing conservative voters; liberals are demoralized.
Private groups are pouring huge sums of money into GOP campaigns. An almost dizzying series of Democratic messages has failed to gain traction, forcing Obama to zigzag in search of a winning formula.
At a Democratic rally in Boston on Saturday, Obama acknowledged that the enthusiasm of his presidential run two years ago may have faded in the face of the country's economic problems. And he said Republicans believe they can "ride people's anger and frustration all the way to the ballot box."
"There is no doubt that this is a difficult election, Obama told the crowd of 10,000. "That's because we've been through an incredibly difficult time as a nation."
With early voting under way in many states, Democrats are trying to minimize the damage by concentrating their resources on a dwindling number of races.
"The poll numbers and the enthusiasm on the right versus the lack of the enthusiasm on the left suggest a pretty big Republican night," said former Nebraska Sen. Bob Kerrey, who once headed the Democratic Senatorial Campaign Committee.
With Democrats in power while the unemployment rate stands at 9.6 percent, "it's difficult to say, 'Well it could have been worse,'" Kerrey said.
Polls, campaign finance reports and advisers in both parties indicate that Republicans are in line to seize on a level of voter discontent that rivals 1994, when the GOP gained the House majority for the first time in 40 years. Democrats are embattled at every level.
Republicans need to win 40 seats to regain the House majority they lost four years ago. Even some Democratic officials acknowledge that their losses could well exceed that.
A GOP takeover would depose Rep. Nancy Pelosi, D-Calif., as the first female House speaker and force Obama to negotiate with Republicans on every significant legislative issue.
Every day brings fresh evidence of Democratic officials virtually abandoning House members whose re-election bids seem hopeless. Republicans are expanding the field to pursue races that once appeared unattainable. In the coming week, Republicans or GOP-leaning outside groups plan to spend money in a 82 House races that they see as competitive or within reach of a last-minute upset.
Democrats, desperate to hold their losses to three dozen seats, plan to run TV ads in 59 races in the remaining days. But their chief House campaign committee has recently canceled millions of dollars worth of advertising for struggling Reps. Steve Driehaus and Mary Jo Kilroy of Ohio, Suzanne Kosmas of Florida, Betsy Markey of Colorado and Steve Kagen of Wisconsin.
They are shifting some of that money to incumbents once considered safe, such as Arizona Rep. Raul Grijalva. But in a sign of the election's volatility, they also are helping viable incumbents they had expected to be trailing significantly - South Dakota Rep. Stephanie Herseth Sandlin, for example.
The Democrats' House campaign committee raised almost $16 million in September and has $41.6 million in the bank.
That's a big fundraising advantage over the GOP's House campaign committee. But the figures are misleading because heavy spending by outside groups, which often hide their donors' identities, clearly favors Republican candidates.
To gain the Senate majority, Republicans must hold all 18 of their seats on this year's ballots while picking up 10 of the 19 Democratic seats. It's a tough task, but not inconceivable.
Democrats trail badly in states where they once held some hope of supplanting Republicans: Missouri, New Hampshire, Ohio and Florida. Kentucky is the only one that's still close. But Democrats have reduced their spending there, a sign that Republican and tea party favorite Rand Paul is clearly ahead.
Among seats now held by Democrats, Republicans are favored to win open races in North Dakota and Indiana, and to oust Sen. Blanche Lincoln in Arkansas.
In Pennsylvania, where Republican Pat Toomey had comfortably led Democrat Joe Sestak in polls, the race has tightened in recent weeks, forcing the GOP to spend more than it had planned. The Republican Party also is pouring am additional $2 million into Illinois, where Republican Mark Kirk has slipped somewhat in polls in his race against Democrat Alexi Giannoulias for Obama's old seat.
That said, Democrats say Wisconsin Sen. Russ Feingold is struggling mightily, and Colorado Sen. Michael Bennet is in a tough fight.
Races are extremely close in West Virginia and Nevada, where Senate Majority Leader Harry Reid is battling tea party-backed Republican Sharron Angle in a bitter and costly campaign.
Democrats are anxiously watching Sens. Barbara Boxer in California and Patty Murray in Washington. Private polls show Republicans pulling closer but still trailing.
Should Republicans win all the close races and knock off either Boxer or Murray, they may rue the nomination of tea partier Christine O'Donnell, who badly trails Chris Coons in Delaware. That once-promising state could have provided the 10th GOP win needed to take the Senate majority.
Democrats risk losing a dozen governors' chairs they now hold, including those in pivotal presidential states such as Ohio, Pennsylvania, Michigan, Iowa, Wisconsin, Maine and New Mexico. Also possibly falling into GOP hands are Oklahoma, Kansas, Wyoming, Tennessee, Illinois and perhaps Oregon.
Democrats have good chances to pick up GOP-held governorships in four or five states, including California and possibly Florida.
The Republican Governors Association's $31 million haul over the past three months enables the GOP to jump into more races. The Democratic Governors Association raised $10 million in that period.
Perhaps nothing has frustrated Democrats more than their yearlong failure to find a message that could puncture the anger of millions of voters who seem bent on punishing the party in power. It wasn't for a lack of trying.
Obama may have charmed stadiums full of voters in 2008, but he and congressional Democrats never recovered from barrages of criticism in 2009 about unemployment, bank bailouts and strong-arm legislative tactics used on issues such as health care.
Eight months ago, Democrats boldly predicted that voters would embrace the new health care law once portions took effect, such as the right to keep children on their parents' insurance plans until age 26. Obama practically dared GOP lawmakers to urge the law's repeal.
"Go for it," he said in Iowa in March. "If these congressmen in Washington want to come here in Iowa and tell small-business owners that they plan to take away their tax credits and essentially raise their taxes, be my guest."
It didn't work out that way. By the time the health bill's first elements became law on Sept. 23, most Democratic candidates were ducking it, and many had to defend their votes amid harsh attacks from Republican opponents.
Democrats turned their energies to framing the election as a series of one-on-one contests about local issues, while Republicans kept portraying it as a national referendum on Obama and the economy.
The national theme persisted, so Democrats tried to turn it to their advantage. Obama repeatedly reminded voters that former President George W. Bush had left him with a major recession, failing banks and a rapidly growing deficit. Don't give the car keys back to those who drove the economy into the ditch, Obama would say dozens of times.
In the early autumn, the president and his allies tried another tack: portraying House Minority Leader John Boehner, R-Ohio, as the well-tanned face of a party that would let Wall Street run amok while the richest Americans kept enjoying deep tax cuts. In an Ohio speech, Obama cited Boehner's name eight times.
Voters seemed to shrug. Obama and his top aides then tried a new approach: accusing Republican supporters, particularly the U.S. Chamber of Commerce, of funding campaigns with millions of undisclosed dollars, some of them possibly from foreign sources.
The group and others angrily denied the allegations, and Democratic strategists said they saw little evidence that the debate was moving voters.
As Election Day draws nearer, top Democrats seem almost desperate and hyperbolic. The chairman of the Democratic Party, Tim Kaine, compared conservative groups' campaign spending with the Watergate scandal, even though no one has provided evidence of wrongdoing, let alone criminality.
Kerrey, the Nebraska Democrat, said the White House has careened from message to message all year without finding an economic pitch to reassure Americans deeply worried about finding or holding jobs.
"They said, 'It could have been worse, we did pass health care reform, we did pass financial services industry reform,'" Kerrey said. "Those arguments don't do much to much to confront what is a building momentum in the opposite direction."
Many Republicans say there's almost nothing that Obama and other Democrats can do at this stage.
"It's as if the concrete has already been poured around the Democrats' feet," said GOP consultant Kevin Madden.