In an election for United States Senator from Georgia today, three weeks until votes are counted, Republican incumbent Saxby Chambliss continues to cling to the narrowest advantage over Democratic challenger Jim Martin, 46% to 43%, according to a SurveyUSA poll conducted for WXIA-TV Atlanta and WMAZ-TV Macon. Results are within the survey’s 4.3 percentage point margin of sampling error. Compared to a SurveyUSA poll released two weeks ago, Chambliss is flat; Martin is down 1 point. Libertarian Allen Buckley gets 6% today, another 5% are undecided. Buckley appears to take votes from Chambliss. If Buckley’s support collapses on Election Day, as often happens with 3rd-party candidates, Chambliss may outperform these results. Conversely, if Democrat Barack Obama at the top of the ticket causes the electorate in Georgia to be more than 26% black, as SurveyUSA herein foresees, Martin may outperform these numbers.

Four weeks ago, when SurveyUSA began tracking the Senate race in Georgia, Chambliss, who is running for his second term, led Martin by 17 points. Two weeks ago, before the candidates debated, Chambliss led by 2. Today, in polling conducted entirely after the 10/09/08 debate which included all three candidates, little has changed.

18% of Georgia voters say they have already voted; among them, Martin leads by 4 points; among those likely voters who have not yet voted, Chambliss leads by 4. Votes are counted in 22 days; any outcome is possible.

You can see full results of this poll right here .