TOLEDO, United States (AFP) - President George W. Bush and Democrat John Kerry, deadlocked in their White House race, plowed well-worn electoral turf in the US Midwest scrounging for votes in next week's election.
The two men were working key battleground states as their marathon campaign sank deeper into acrimony, with charges and counter-charges over Iraq and reports of a missing cache of high-grade explosives.
Tracking polls Thursday showed the candidates in a virtual tie nationwide ahead of Tuesday's ballot, which shaped up as a nerve-wracking photo finish with lawyers on hand to challenge every vote.
The Washington Post gave Kerry a statistically insignificant 49-48 percent lead. Zogby International had Bush on top 48-47 percent while the Rasmussen polling group put the president's edge at 49-47 percent.
The race was just as clouded on the state level, where the two sides jockeyed for a majority of the 538 electoral votes that actually decide the presidency and are awarded in separate, mostly winner-take-all, contests.
Florida and Ohio, which Bush won narrowly in 2000, were the most closely watched states and were too tight to call. Wisconsin, Iowa, Minnesota, New Mexico, New Hampshire and a few other states also stacked up as crucial.
Bush was racing Thursday through the midwestern battleground with stops in Michigan, Ohio and Pennsylvania. On Friday he was to hit New Hampshire, come back to Ohio and Michigan and move on to Wisconsin, Minnesota and Florida.
Kerry, the veteran senator from Massachusetts, focused Thursday on Wisconsin and Ohio before heading for Florida where he had a series of appearances scheduled on Friday.
Both sides were throwing starpower into the battle for Ohio, which no Republican has ever lost and still captured the White House.
Legendary rocker Bruce Springsteen was scheduled to appear with Kerry in Madison, Wisconsin, and the Ohio state capital of Columbus, as well as at a pre-election rally in Cleveland, Ohio on Monday.
Kerry has used the anthemic Springsteen song "No Surrender" as his walk-on music at rallies across the country and the veteran rocker is expected to play several songs during his appearances with the Democratic challenger.
The Republican Bush, meanwhile, brandished one of his party's biggest guns, Hollywood star turned California governor Arnold Schwarzenegger.
Although opposing Bush on several issues ranging from abortion to gun control and gay marriage, the brawny "Terminator" was to join Bush on Friday in Columbus.
The politically moderate Schwarzenegger acknowledged Tuesday he was not "in sync" with the conservative president on many issues, but added, "We are Republicans and have to support one another."
The missing stash of explosives in Iraq continued to grip the frenetic campaign with Kerry charging the Republican incumbent with incompetence and "dodging and bobbing and weaving" on the issue.
When Bush on Wednesday dismissed the allegations as "wild charges," Kerry fired back, "Mr. President, for the sake of our brave men and women in uniform, for the sake of those troops who are in danger... you owe Americans real answers about what happened, not just political attacks.
Bush said it was unclear what happened to the 350 tonnes of explosives, which the United Nations warned could be used in conventional bombs or to trigger a nuclear device.
"The senator is denigrating the action of our troops and commanders in the field without knowing the facts," Bush said Wednesday as he campaigned through Pennsylvania.
"Unfortunately, that's part of a pattern of saying almost anything to get elected," Bush said, adding the government was investigating various scenarios, including whether the explosives were moved before US troops arrived last year.
"This investigation is important, and a political candidate who jumps to conclusions without knowing the facts is not the person you want as your commander in chief," said Bush.
As the race looked headed to another wild climax that could rival the 2000 result, when Bush lost the popular vote but took the Electoral College 271-266, a new poll showed Kerry starting to make inroads among swing voters.
The Pew Research Center said the senator had made "more substantial gains" than the president among a sample of 519 swing voters who were first interviewed in September.
Forty percent of those questioned last Thursday to Monday said they were backing or leaning to Kerry, up from 28 percent in the September poll. Bush's support grew by only four points to 38 percent.

10/28/2004 - 17:01 GMT - AFP