Across the United States, candidates are making final campaign pushes before Tuesday's elections for the House of Representatives, roughly one-third of the Senate, and several closely-watched governorships.
Democrats won control of both houses of Congress in 2006, and the White House in 2008, but their continued dominance of both elective branches of government is in doubt.
A president's party usually loses seats in Congress during midterm elections, and widespread frustration over sluggish U.S. economic growth and stubbornly high unemployment are contributing to what many political analysts see as a toxic political climate for Democrats.
Rally for support
For weeks, President Barack Obama has campaigned energetically for Democratic candidates. At a rally Sunday in Ohio, he attempted to rekindle the spirit and enthusiasm of the party's voters with a call to action.
"I need you to keep on fighting. I need you to keep believing. I need you to knock on some doors. I need you to talk to your neighbors. Talk to your friends. I need you to go vote early, and get your friends to vote."
Public-opinion polls show the U.S. electorate fairly evenly split between Democratic and Republican-leaning voters. But Republicans are thought to be more energized than Democrats and therefore more likely to actually cast a ballot in this election. Among likely voters, most polls show Republicans with a significant edge.
Although Republicans potentially could seize control of both houses of Congress, it is in the House of Representatives where they are thought to have the best chance of emerging victorious.
A party switch in the House would end the four-year tenure of Democratic Speaker Nancy Pelosi. Her likely replacement would be House Republican Leader John Boehner, who has pledged to reverse what he sees as the free-spending, debt-inducing ways of the Obama administration.
"We create opportunities for our citizens unlike any country in the world. And if we do not get a hold of this government and create a smaller, less-costly and more-accountable government, those opportunities will not be there for our kids and our grandkids," Boehner said.
Democrats, including former President Bill Clinton, argue America's economic woes are the product of eight years of Republican rule before President Obama and Democrats should be given more time to make things better.
"You gave them [Republicans] eight years to dig the hole. Give us four years, just half the time, to get out," Clinton said.
But Republicans say the American people's patience has run out. Appearing on Fox News Sunday, Former Alaska Governor Sarah Palin said voters will send a clear message to the White House.
"They are going to say, 'You blew it, President Obama. We gave you two years to fulfill your promise of making sure the economy starts roaring back to life again'," Palin said.
In addition to congressional races, some of America's biggest states will be electing governors, including California, Florida and New York.