Incumbent Republican Sen. Saxby Chambliss leads Democratic challenger Jim Martin by three percentage points in a new InsiderAdvantage poll.

The poll, conducted for Politico.com, has Chambliss at 50 percent and Martin at 47 percent, which is within the four-point margin of error. That is close to the same split the two candidates earned in the general electilon Nov. 4, which ended with Chambliss just shy of the 50 percent mark to avoid a runoff.

In that vote, Libertarian candidate Allen Buckley earned 3.5 percent of the vote. He has not endorsed either Martin or Chambliss.

The poll was conducted Nov. 23 among 523 likely voters.

“This thing’s going to be a nailbiter,” Insider CEO Matt Towery said. “We don’t know who’s going to turn out and we don’t know how it’s going to turn out, but it’s going to be a close race.”

Chambliss was scheduled to attend a campaign event in Gainesville at 11:30 a.m. today with Gov. Sonny Perdue and former Sen. Zell Miller. The event will be held at the Gainesville Civic Center.

The Georgia race is crucial in the Democrats' push for a 60-seat super majority in the Senate. They currently have 58 seats, with the Minnesota race between GOP incumbent Norm Coleman and Democrat Al Franken still in a tight recount.

Because of that, the candidates have drawn support from a handful of national figures campaigning on their behalf. Martin has earned visits from former President Bill Clinton and his former vice president, Al Gore. President-elect Barack Obama has not planned a trip to Georgia on Martin's behalf.

In recent days, he has campaigned with Republican presidential nominee John McCain as well as former candidates Mitt Romney, Mike Huckabee and Rudy Giuliani. He is scheduled to campaign statewide Monday with vice presidential nominee Sarah Palin.

Early voting for the runoff ends today. Polls will be open from 7 a.m to 7 p.m. Tuesday.