US President Barack Obama told voters that the choice on Election Day was between the economic policies "that got us into this mess" and the policies leading the nation out.
Obama closed a four-day campaign swing on Saturday that sought to bolster the fortunes of Democratic candidates ahead of the Nov 2 elections with a spirited rally imploring supporters to defeat the conventional wisdom that Democrats face steep losses.
"All they've got is the same old stuff that they were peddling over the last decade," he said of Republicans.
"I just don't want to relive the past."
He said: "The other side is betting on amnesia. It is up to you to show them that you have not forgotten."
Obama made his comments at a Minneapolis rally for gubernatorial candidate Mark Dayton. The former US senator is facing a challenge from Republican Tom Emmer.
Obama is not on the ballot in these mid-term elections but much is at stake because Republican gains - including a possible a takeover of the House of Representatives - could slow progress on the remainder of Obama's agenda.
The White House naturally doesn't want that to happen, so Obama has been campaigning in Democratic-leaning states where key congressional allies, such as Senate Majority Leader Harry Reid, are fighting hard to emerge victorious from close races that became that way, in part, because of voter angst and anger over the economy, unemployment and other issues.
Republicans have made Reid their top target in the Nov 2 election.
The minority party needs to gain 10 seats to wrest control of the Senate from the Democrats, and unseating the most powerful Senate Democrat would deal a major blow to Obama, who reminded supporters of Republican opposition to his agenda.
Reid, of Nevada, is tied in the polls with relative unknown Republican Sharron Angle in a race that has attracted millions of dollars from across the nation.
Obama's visit on Friday to the US gambling capital was meant to give a boost to Reid, who hopes to avoid the fate of former Senate Democratic leader Tom Daschle who lost by a narrow margin in South Dakota in 2004.
Like incumbent Democrats everywhere - and more than most - it's not only a Republican rival that Reid is combatting. It's the troubled economy, in the state with the nation's highest rates of unemployment (14.4 per cent) and home foreclosures, where the recession has taken a big bite out of Nevada's main tourism industry.
Republican candidate Angle has urged Reid to "man up" and accept his share of blame for the state's economic woes. Reid has responded to such attacks by saying Angle like other tea party-backed candidates is too extreme for Nevada voters.
He has called her an ally of the special interests and advocate for jettisoning government agencies and privatizing programs for the elderly and veterans that millions of Nevadans rely on.
The Nevada Senate race is now a test of strength for the fledgling tea party movement, which advocates smaller government and lower taxes.
The 61-year-old Angle, a former state lawmaker - like tea party-backed candidates in other states - defeated a favorite of the state's Republican establishment in the primary election.
Her ultraconservative policies have hurt her in the general election campaign with some moderate Republicans and leaders of the state's gambling industry backing Reid.
She has countered by casting Reid as a career politician who lives in a fashionable condominium in Washington and is out of touch with the state he has represented in Congress for decades.
Polls show that the 70-year-old Reid, who is seeking a fifth Senate term, remains very unpopular among Nevada voters, but the Senate race is among the tightest in the US with both candidates polling just under 50 per cent.
Reid has fiercely courted the Hispanic vote in the contest against Angle, who has run TV ads with images of dark-skinned men and a map of Mexico to highlight her support of strict immigration policies.
Hispanics are a growing voting bloc in Nevada, where they make up roughly 25 per cent of the population. More than 80 per cent of the Silver State's Hispanics hail from Mexico.
Another tea party favorite, former-Alaska Gov. Sarah Palin, who is not running for office in this election, took aim at Obama at a Republican rally Saturday in Florida, saying he needed to apologize to the 14.8 million people unemployed in the US
"You know, the president is now telling us that we're not thinking straight because of all the fear and frustration," Palin said.
"You know Mr President, you have it right on one point there. We are afraid, knowing that your economic policies are driving us off a cliff."