"Burns has obviously come back from the dead," says Mason-Dixon polling director Brad Coker. While it seemed that Democratic challenger Tester had a slight edge, a recent poll shows them neck and neck. Recent polls had found Tester, a third-generation Montana farmer, beating Burns by 2 to 9 points.

"It just confirms my belief that we are going to have to wait until after 8 p.m. on Election Day to know anything for certain," says Christopher Muste, a political science professor at the University of Montana–Missoula.

Those earlier polls reflected the generally sour mood of voters nationwide against Republicans, as well as Burns's association with disgraced lobbyist Jack Abramoff. The 18-year incumbent has also suffered from his uncanny knack for putting his foot in his mouth. In July, the senator told firefighters they had done a "poor job" fighting a wildfire — this in a state indebted to firefighters for quenching abundant blazes. Seven years ago in a speech about energy, he called Arabs "ragheads." Most recently, Burns was mocked for having said President Bush had a plan for victory he was not sharing with Democrats. He later acknowledged that he misspoke. But Burns has raised much more money than Tester—$7.4 million to $4.3 million, as of mid-October. Burns has also campaigned hard that he has brought back billions to a state dependent on ranching and farming aid. And he's had a string of Republican heavyweights stump for him in the past few months, including a last-minute visit by President Bush—something that could matter in a state that Bush carried the state 59 to 39 percent over Sen. John Kerry in 2004.

—Danielle Knight