President Bush's Republican Party is expected to maintain control of the U.S. House of Representatives and the Senate following Tuesday's elections.
Although Democrats had hoped to take control of the Senate, where Republicans currently have a two-seat majority, it appears they will remain the opposition party in the chamber.
Republicans appeared to have picked up several seats currently controlled by Democrats, including in South Carolina, where Republican Congressman Jim DeMint won the seat held by retiring Democratic Senator Fritz Hollings.
In Georgia, Republican Congressman John Isakson claimed the seat being vacated by retiring Senator Zell Miller, the maverick Democrat who delivered the keynote address at President Bush's Republican National Convention.
Republicans apparently maintained seats in close races in Oklahoma and Kentucky, where Democrats hoped to make gains.
Democrats did pick up a seat in Illinois, where State Senator Barack Obama, son of a Kenyan father and American mother, easily won the seat being vacated by Republican Senator Peter Fitzgerald.
Mr. Obama, who delivered the keynote address at the Democratic National Convention in July, will be the only African-American in the Senate when a new Congress convenes in January. He was exuberant when he addressed supporters Tuesday night. "I am fired up," he said. "Look at this crowd. Thank you Illinois!"
Thirty-four of the 100 Senate seats are up for election. The contest that has received the most attention is in South Dakota, where Democratic Minority Leader Tom Daschle is in a close race with his Republican challenger, former Congressman John Thune. That race remains too close to call.
In Florida, Republican Mel Martinez, a former member of President Bush's Cabinet, is seeking to become the first Cuban-American senator. He is in a tight race for a seat held by retiring Democratic Senator Bob Graham.
In the House, all 435 seats are up for election. Most incumbents in the Republican-led chamber are expected to be re-elected.
However, two long-time Democratic Congressmen from Texas, Martin Frost and Charles Stenholm, lost their seats, after state Republicans redrew congressional district lines to their party's advantage.