The Republican Party and the McCain campaign have swatted away the Barr candidacy, but some Republicans are taking it seriously. If the early polls hold up, and Senator Barack Obama, the presumed Democratic nominee, pours heavy resources into Georgia, that state could be up for grabs, said Senator Johnny Isakson, Republican of Georgia.

“If Barr got 8 percent, and you’ve got the higher African-American turnout from Barack Obama, then you’d have a significantly close race in the state,” Mr. Isakson said.