U.S. voters will go to the polls in midterm elections on Tuesday for races in the House of Representatives and the Senate as well as state and local offices. Analysts say the elections could change the balance of power in Washington, where Democrats control the White House and dominate both houses of Congress.
Thirty-seven Senate seats are up for election across the country. And analysts say tight races in Western states like California could help to give the Republican Party a majority in the Senate. Republicans need to gain 10 seats to dominate that body. But public opinion surveys suggest that will be difficult.
More likely would be a shift in the House of Representatives. All 435 House seats are up for election. And most analysts say the Republicans could gain the 39 seats they need to claim a House majority. A Republican-dominated House would make it harder for President Barack Obama and the Democratic Party to pursue their legislative agenda.
One of the nation's tightest races is in Nevada, where Senate Majority Leader Harry Reid is facing a tough challenge from conservative activist, Republican Sharron Angle. Nevada has the nation's highest unemployment rate and one of the highest rates of defaults on home mortgages. Most polls show Angle with a slight lead.
Across the country, both major parties have flooded the airwaves with negative campaign advertisements.
A California ad for Democratic Senator Barbara Boxer attacks her Republican challenger, former Hewlett-Packard chief executive Carly Fiorina.
Boxer TV ad: "Carly Fiorina. As CEO, she shipped more than 30,000 jobs to China. Before she was fired, Fiorina laid off 30,000 workers, outsourced jobs to China, then took $100 million for herself. Carly Fiorina - outsourcing jobs, out for herself."
Fiorina's ads say it is time for a change.
Fiorina TV ad: "And if we reelect Barbara Boxer, nothing will change. She'll continue to vote for higher taxes, job-crushing policies - just like she's done for 28 years. Nothing will change. And Barbara Boxer will continue to be what she's always been - self-serving, ineffective, more of the same."
President Obama and first lady Michelle Obama have been campaigning around the country, as has former Republican vice presidential candidate Sarah Palin.
Mr. Obama frequently reminds voters of his 2008 campaign promise to bring change to Washington.
"If everybody who fought for change in 2008 shows up in 2010, we [the Democrats] will win this election," said President Obama.
California voter Karen Westland says she is supporting Republican candidates because of the weak economy and what she views as the president's failed promises.
"All the change I have is left in my pocket," said Westland. "Believe that - [coins in my pocket] is all the change I've gotten from President Obama."
Democrat Genae Victoria Jefferson says the president and his fellow Democrats have important accomplishments, including health care reform and a government economic stimulus package. She supports Democratic candidates and causes.
"Oh, definitely," said Jefferson. "And I'm ready for the propositions, I'm ready for the gubernatorial race, the congressional races."
Some states permit early voting and so many people in places like Nevada and California have already cast their ballots. Both major parties promise a major get-out-the-vote drive on Election Day.