Poll: Bush, Kerry split six key states
National survey of likely voters also too close to call
President Bush speaks at a rally Sunday in Gainesville, Florida, while Sen. John Kerry talks to supporters in Dayton, Ohio.
CNN's Bill Schneider on what happens if there is a split vote.
CNN's Elaine Qujiano on the weekend's campaigning.
CNN's Bob Franken on voters and values.
(CNN) -- Likely voters surveyed in six major showdown states indicated that they are almost evenly split in their support for President Bush and Democratic Sen. John Kerry, according a CNN/USA Today/Gallup poll released Sunday.
A separate Gallup poll of likely voters indicated a similar split nationwide, with 49 percent choosing Bush and 47 percent taking Kerry -- a virtual tie given the margin of error of plus or minus 3 percentage points. Independent candidate Ralph Nader had 1 percent.
In the battleground state polls, only in two places did a survey indicate a lead outside the margin of error. (Opinion poll figures)
Those states were Wisconsin, where Bush led by 8 points, and Minnesota, where Kerry led by 8 points.
In the other states, Bush had leads of 2 points in Iowa and 4 points in Pennsylvania. Kerry had leads of 3 points in Florida and 4 points in Ohio.
The figures were mostly the same among registered voters, except in Pennsylvania, where Kerry had a 2-point lead.
Vice President Al Gore carried both Wisconsin and Pennsylvania in 2000, and no Republican candidate has won the White House without winning Ohio. (Showdown states: Wisconsin, Ohio, Pennsylvania)
Perhaps the most significant shift in the poll was in Florida, where the same survey indicated Bush ahead by 8 points among likely voters last week, though other state polls indicated a much tighter race. (Full story)
In 2000, Florida clinched the election for Bush, after a month of recounts and court challenges. (Showdown state: Florida)
Bush campaigned most of Sunday in Florida. Kerry ended his day in Florida, too, after stops in Ohio and New Hampshire. (Full story)
Independent candidate Ralph Nader was favored by 2 percent of likely and registered voters each in Iowa. Among likely voters in Minnesota, he had 1 percent and 2 percent among registered voters. In Wisconsin he had 1 percent in each group. Those are the only states in the survey in which he is on the ballot.
About 1,300 registered voters were interviewed in each state, of whom about 1,100 in each indicated they were likely to vote in the election. The polls all were conducted between late last week and Sunday.
The national poll, conducted Friday through Sunday, interviewed 2,014 adult Americans, including 1,866 registered voters. Of those, 1,573 indicated they were likely to vote.
A key statistic in the national poll was the 3 percent of likely voters who said they were undecided.
Using voting behavior data from previous elections, the Gallup organization attempted to estimate how the undecideds would vote Tuesday.
The result was a tie of 49 percent each for Bush and Kerry, with 1 percent for Nader and 1 percent for other candidates.
In the history of polling, Gallup has never come out with a tied race in its final pre-election estimate -- just one more footnote for the history books in a history-making campaign.
Another possibly significant statistic was the difference of opinion on Bush's job performance between all respondents and likely voters.
Among all respondents, Bush had an approval rating of 48 percent, compared with 51 percent in the previous Gallup poll, taken October 22-24.
By contrast, among likely voters, Bush's approval rating was 51 percent, down from 54 percent in the previous poll.
Fifty percent job approval is considered the key threshold for an incumbent seeking re-election.
There was also a difference between likely voters and all respondents on the question of which issue those polled consider most important.
Among all those interviewed, the economy got the top spot at 31 percent, with terrorism second at 27 percent and the war in Iraq at 24 percent.
But among likely voters, the economy dropped to third place (27 percent), just a few points behind terrorism (31 percent) and Iraq (28 percent).
CNN.com's David Osier contributed to this report