U.S. President George Bush is attending rallies in 10 states before Tuesday's Congressional elections.
He is urging fellow Republicans to focus on the economy and new figures that show U.S. unemployment at its lowest level in more than five years.
Mr. Bush says his record tax cuts have helped fuel that economic performance. Democrats in Congress say they will allow many of those cuts to expire if they win control of the House because, they say, the lost revenues have contributed to deficit spending.
In his weekly radio address, President Bush said Democrats are wrong on the economy.
"The last thing American families and small businesses need now is a higher tax bill. And that is what you will get if the Democrats take control of the Congress. America needs leaders in Washington who understand that you know how to save, spend and invest your money better than the federal government."
Public opinion polls suggest Democrats could win enough seats to take control of the House of Representatives for the first time in 12 years.
Pollsters attribute that to voter discontent over the war in Iraq. Two-thirds of Americans disapprove of the way President Bush is handling the situation there. In the Democratic radio address, Pennsylvania Congressional candidate Lois Murphy said her party will fight for a new direction in Iraq.
"No matter how bad Iraq gets, or how many respected Americans say that our strategy is not working, no matter how many times former Secretaries of State Colin Powell or James Baker say that we need to change course, no matter how many different intelligence agencies tell us that Iraq is creating more terrorists than we had before, and no matter how many generals say Rumsfeld should go, our president and his Republican Congress have promised not to change a thing, if they are returned to power."
At a Republican rally in the western state of Colorado, President Bush said U.S. troops are winning the war, and Democrats have no plan for Iraq.
"They will leave before the job is done. I'm not saying these people are unpatriotic. I'm just saying they are wrong."
Democrats say they do have a strategy. Their leader in the House says Democrats will demand that Iraq take more responsibility for its own security, and will begin bringing some U.S. troops home this year.
A public opinion poll released Saturday by Newsweek magazine says 54 percent of likely voters will chose Democratic candidates and 38 percent will vote for Republicans.