Opposition Democrats need to gain 15 seats in the House of Representatives and six seats in the Senate to retake control of both chambers of Congress for the first time since 1994.
Congressional midterm elections usually focus on local issues and candidates. But this year, Democrats are tapping into public discontent over the war in Iraq to fuel a large turnout of voters on November 7th. Senator Joe Biden is a Democrat from the eastern state of Delaware.
"And the American people, in my view, have one chance, one chance, to send a clear message on Iraq and they should not be distracted."
All 435 House seats are at stake this year, and 33 of the 100 Senate seats. In addition, 36 states are holding elections for governor.
Public opinion pollster John Zogby says Democrats have the momentum going into the final days of the election. But Zogby cautions that Republicans could still stage a late rally that might limit Democratic Party gains in Congress.
"The races that we are polling, both in the U.S. Senate and in the House of Representatives, focus mainly on Republican-held seats and we do see Democrats leading in most of those seats. The leads are not substantial and the undecided voters include significant numbers of undecided (voters) among Republican constituencies."
President Bush is among those urging Republicans to ignore the polls and rally to their party candidates around the country.
"Now, I understand here in Washington people have already determined the outcome of the election. Like it is over, even before the people actually start voting. That is not what I see when I am on the campaign trail."
Only an estimated 50 or so House races out of 435 are seen as truly competitive. Democrats hope to make gains by picking up vulnerable Republican House seats in Connecticut, Pennsylvania and Ohio.
Several Republican senators are also seen as vulnerable this year, but most analysts believe Democrats will have a hard time picking up the six seats they need to regain a majority in the Senate.
Among those Senate elections getting national attention is the race in Tennessee between Democrat Harold Ford and Republican Bob Corker. Ford is trying to become the first African-American elected to the Senate from a southern state since the post-civil war period in the mid-1800's known as Reconstruction.
Another prominent race is in Virginia where Republican Senator George Allen is trying to fend off a stronger than expected challenge from Democrat Jim Webb. Other key Senate races are taking place in Missouri, Ohio, Pennsylvania and Montana.
Republicans believe they have a good chance to win a Senate seat in New Jersey now held by a Democrat. Democrats are also looking to make inroads in governor's races around the country. Republicans currently hold 28 governorships to 22 for the Democrats. But the polls suggest that ratio could shift dramatically on Election Day.
One bright spot for Republicans is the political resurgence of California Governor Arnold Schwarzenegger. Schwarzenegger struggled early in his term but his political standing improved after he sought the support of political moderates from both parties. Stuart Rothenberg publishes a non-partisan political newsletter in Washington.
"It is the quirky nature of American politics. You can have a national trend, a national mood, and yet in an individual race, a Republican may do extremely well."
In addition to the voting for office-holders, voters in many states will be asked to vote on numerous ballot questions on issues ranging from abortion and homosexual marriage to taxes, the minimum wage and limits on public smoking.