Updated

President Bush hit the campaign trail in the Midwest Sunday, making stops in Illinois, Minnesota, South Dakota, and Iowa.

Bush paid solemn tribute to Sen. Paul Wellstone, the Democrat killed last month in a plane crash, but fought to derail Walter Mondale's bid to succeed Wellstone, telling Minnesotans that Republican Norm Coleman is the state's future.

"Believe me when I say, we need fresh air in the United States Senate," Bush said, an apparent reference to the fact that Mondale already served in that body, from 1964-1976. "The future of Minnesota rests with Norm Coleman."

In an extraordinary departure from his standard stump speech, Bush opened his remarks by saying Minnesotans were going through "a traumatic time" following Wellstone's death.

"After all, just nine days ago, you lost a principled senator along with his wife and daughter and five other fellow Americans," Bush said. "Paul Wellstone was respected by all who worked with him, he'll be missed by all who knew him.

"Now a vote is coming on in the middle of a state that is mourning," Bush said. "And even though your state is still in mourning, I'm here to remind people from all political parties that you have a duty to vote."

Democrat-turned-Republican Coleman, basking in the presence of a president who has raised millions of dollars for him, pledged to thousands of GOP activists in a sports arena: "Give me your support, give me the next two days of your life, and I will give you six years of the kind of leadership that will make you very, very proud."

Jim Manley, a spokesman for Mondale, said Bush's salute to Wellstone was "appreciated, and they're nice words." But, he said, "The irony is that Norm Coleman ran a campaign of malicious half-truths trying to malign Wellstone." Mondale's "experience and record of unparalleled achievement" makes him the most qualified candidate for Wellstone's job, Manley said.

Bush was greeted at the arena by signs bearing Mondale's nickname, "Fritz."

The White House was tightlipped about its political plans for Minnesota just after Wellstone died, but officials said Sunday that Bush intended all along to return to the state if Coleman thought it would help.

Coleman did, and the White House sent Vice President Dick Cheney on Friday and Laura Bush on Saturday before the president's visit.

New polls Sunday suggested the race was very tight, with Mondale slightly ahead in one but slightly behind in another.

Bush's remarks came midway through a feverish swing through Midwestern battleground states, looking to deliver 11th-hour aid to Republicans in races that will determine control of Congress and statehouses.

In his first get-out-the-vote stop Sunday, Bush was in Springfield, Ill., promoting GOP candidates including state Attorney General Jim Ryan, who has narrowed the gap in the governor's race against Democratic Rep. Rod Blagojevich.

"While you're in that voting booth, support a good man for governor — his name is Jim Ryan," Bush said. "A lot of people in this state have written him off. I think they spoke a little too soon, don't you?" An audience of thousands responded with a roar of agreement.

Bush also backed Rep. John Shimkus, battling another incumbent, Democratic Rep. David Phelps, for a new congressional seat in Illinois. It is one of four contests around the country pitting two sitting members of Congress against one another. Shimkus appears to have a slight edge, but the race remains tight.

"For the sake of Illinois, for the sake of this congressional district, for the sake of the country, put John Shimkus back in the United States Congress," Bush said.

In South Dakota, Bush took aim at Senate Majority Leader Tom Daschle, D-S.D., whose Democratic colleague in the Senate, Tim Johnson, is neck-and-neck with Rep. John Thune, hand-picked by the president for the race. Bush was in South Dakota on Thursday — in Daschle's hometown, no less — and Laura Bush campaigned for Thune on Sunday.

"Right after I finish speaking, you get home and turn out the vote," Bush told his audience in his third speech of the day.

Bush has mounted an aggressive push ahead of Election Day, and by the time he gets to his Texas ranch late Monday, he will have visited 17 cities in 15 states in five days. Sunday alone, he spent almost half his 12-hour day in the air, spending time — usually under an hour — in five different states.

Sen. Patty Murray, D-Wash., head of the Democratic Senatorial Campaign Committee, predicted voters will not want to see the legislative and executive branches controlled entirely by Republicans.

"What voters are looking at is, do we have a check-and-balance on this White House that will allow another voice, a debate and a discussion," she said on CBS' Face the Nation. "Or are we going to see extreme agendas move through?"

From South Dakota, where Bush met up with the first lady as she completed two heavy days of campaigning, the president was going to Iowa for the night. On Monday, his final campaign swing was to take him through Missouri, Arkansas and Texas.

The Associated Press contributed to this report.