Updated

Millions of American voters were expected at the polls on Tuesday in midterm elections that could fundamentally alter the balance of power as President Bush finished his vigorous effort to lift Republican candidates to victory.

Bush instructed supporters at an energetic rally in his home state Monday night that "you should vote" -- his way, of course -- on Election Day.

The rousing election eve speech came at the end of the president's fifth consecutive 12-hour-plus day on the campaign trail. Bush has stumped for candidates in 23 states -- visiting six of those twice -- since the end of September.

"You should vote," Bush said. "I don't care whether you're Democrat, Republican, independent or could care less about a political party, you have an obligation in a free society."

He was capping the day by boosting GOP state Attorney General John Cornyn -- running for a Texas Senate seat -- who appeared to be holding off Democrat Ron Kirk, a former mayor of Dallas.

Tuesday morning, he and first lady Laura Bush were to cast their votes near their ranch in Crawford -- "I'm not undecided," he declared to his Monday audiences -- before heading back to Washington to monitor results. The president and first lady -- on their 25th wedding anniversary -- were hosting a small dinner and election-watching party with some Republican congressional and political leaders and their wives.

Bush arrived in Bentonville, Ark., on Monday afternoon to throw his weighty support behind Republican candidates there, including one in a tough race for Senate that appears to be breaking for the Democratic candidate.

On the road for six days straight to hit some of the closest contests around the country, the president pitched his usual stump speech, merely changing the names of the candidates, all of whom he described as "good people."

"Let me see if I can put it as plainly as I can. I need Tim Hutchinson in the United States Senate," Bush said in Arkansas, as he pleaded for voters to send the first-term senator back to Congress to help the president pass his plan for expanding the job base, making tax cuts permanent, selecting judges for the federal courts, and getting a homeland security bill without strings.

The president's get-out-the vote pleas are aimed to get Republicans not only to go to the polls on Tuesday, but to encourage others to do so, even "discerning Democrats" and "like-minded independents."

"Round people up to vote. Not only do you have an obligation to vote yourself but you can make a difference in this election ... find those people. Get out the vote ... Work hard and you'll be surprised by what happens on Tuesday."

Hutchinson is in a tight race with Democratic Attorney General Mark Pryor, whose father is the former senator and governor, David Pryor. Earlier in the day, Pryor, who has been increasing his lead in the polls, criticized last-minute accusations about his hiring an illegal alien to do housework in his home, saying they are untrue and a desperate attempt to slander his candidacy. Hutchinson denied any involvement in making the charges.

Earlier in the day, Bush was in St. Charles, Mo., for a final campaign stop for former GOP Rep. Jim Talent, who is battling appointed Democratic Sen. Jean Carnahan for a seat that is too close to call. Late-breaking polls showed Talent up by four points, but within the margin of error.

Talent, who was recruited by the White House after a failing bid for governor in 2000 that also saw then-Sen. John Ashcroft ousted, could be sworn in right away if he takes office. Carnahan was appointed to her seat after her husband Mel was posthumously elected three weeks after dying in a plane crash. Carnahan defeated now Attorney General Ashcroft. His replacement was only an interim position until the next election to fill out the remaining four years of the six-year term.

In the same week as the Country Music Awards, Bush had along for the ride country music star Randy Travis, who attended the Talent rally. In Arkansas, the Gatlin Brothers attended the get-out-the-vote drive with the president.

While the president hit Iowa, Republican Norm Coleman debated a feisty Walter Mondale in Minnesota, the Democratic choice to replace the late Sen. Paul Wellstone.

During the debate, Coleman vowed to work for the citizens of Minnesota and said it would help them to have a senator close to the White House. Mondale countered that the race "is a question about the future, but the basic question is, 'Which future?'"

Polls show Mondale and Coleman running very close. Coleman trailed Wellstone slightly before the latter's deadly plane crash on Oct. 25, after which Mondale, the former vice president and senator, stepped in at the behest of Democrats and Wellstone's surviving children.

Mondale said he shared Wellstone's values and suggested Coleman owed favors to special interests and corporate America. Coleman pointed out that Mondale himself has been a corporate lawyer and member of several corporate boards for two decades.

Both candidates agreed that voters are most concerned the economy, health care and jobs.

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

Back in Iowa, a grinning Bush clearly enjoyed the crowds' adoration and the accompanying "Happy Birthday" serenades at each stop for the first lady, who turned 56 on Monday.

Bush hoped to help veteran GOP Rep. Jim Leach, in a tight race, as well as Reps. Tom Latham and Jim Nussle.

The Associated Press contributed to this report.