Republicans made some major gains in U.S. congressional elections Tuesday, winning back control of the Senate and solidifying their hold on the House of Representatives. The Republican success is good news for President Bush's re-election effort in 2004 and has put opposition Democrats on the defensive, trying to figure out what went wrong.

Republicans defied history by winning back the Senate and picking up House seats in the midterm elections. Traditionally, the party that controls the White House loses seats in Congress, but President Bush proved to be a very effective campaigner for Republican candidates around the country.

"Certainly the candidates who ran (well), ran very strongly on the president's agenda and they won on that agenda," said Presidential spokesman Ari Fleischer.

The president also shaped the issues that drove the midterm election campaign. Republican Senate Leader Trent Lott, who is destined to become Senate Majority Leader when the new Congress is sworn in January, said voter concerns about national security helped Republican candidates around the country.

"You cannot ignore the fact that America did change on 9/11, over a year ago. And I think that did have an effect on this election. People do want security here at home," Senator Lott said.

Democrats were desperate to focus on the weakened U.S. economy in their bid to hold onto the Senate. But Democratic Senate Leader Tom Daschle told CBS television that voters seemed more concerned with foreign policy than domestic issues. "In large measure what people were concerned about were the issues the president was talking about - Iraq, 9/11, making sure that this country stayed strong militarily. That played to his strengths and he did a good job campaigning around the country," he said.

Many analysts believe that Democrats underestimated the impact of the September 11 terrorist attacks on this midterm election.

"I think that the seeds of what happened last night were planted on September 11 and that really transformed the debate in American politics," said Richard Semiatin, a political scientist at the American University in Washington. "If September 11 had never occurred, the results you saw yesterday would never have happened."

The results are also clearly good news for President Bush, who put his popularity on the line in a whirlwind campaign tour for Republican candidates that may have made the difference in several close races.

University of Virginia analyst Larry Sabato said the president has also helped his own re-election chances two years from now. "This was the George W. Bush midterm. The results in both the House and Senate were due primarily to his efforts. His efforts at fundraising, at traveling around the country peripatetically, and perhaps most of all, his agenda which sold. Both foreign policy and domestic," Mr. Sabato said.

Democrats, on the other hand, have little to be happy about. Their attempts to focus the campaign on the weakened U.S. economy failed in many cases. "To this day, I don't understand what the Democrats were saying other than, the economy is bad so vote for us. That is not good enough," analyst Larry Sabato said.

Democrats now find themselves on the defensive. Losing control of the Senate will make it somewhat easier for the president to push his agenda through the Congress and will make it tougher for Democrats to offer alternatives.

Democrats were sharply split on whether to give the president the authority to use military force against Iraq and many now are asking tough questions about the future of the party.

University of Maryland political scientist Ron Walters said Democrats are in need of two things - leadership and an agenda.

"Lack of leadership was a key factor. The Democrats are speaking with a lot of voices and no clear leadership at this point and are vulnerable on that score. They don't seem to have a clear agenda and a message that they are communicating to the American people that is a clear enough alternative that it strikes the attention of the American people and I think that is a problem," he said.

The battle for the future of the Democratic Party will begin soon. Several prominent Democrats are expected to decide whether to make a run for president in 2004 by the end of this year. The battle for the Democratic Party's presidential nomination will largely determine what kind of Democratic Party goes up against the Republicans two years from now.