Washington ? If the presidential race ends up being as close as polls are finding, third-party candidates now polling in single digits could emerge as potential kingmakers in battleground states.

Independent Ralph Nader, who earned the “spoiler” label for drawing votes from Democrat Al Gore in 2000, is a factor this time in such states as Nevada, New Mexico and Pennsylvania.

Libertarian Party candidate Bob Barr, meanwhile, who draws more support from Republicans, is a factor in Florida, North Carolina and New Hampshire.

For example, Barr’s pulling 3 percent in North Carolina, according to a recent Zogby International poll – a potentially decisive margin in a reliably Republican state where Democrat Barack Obama is making a determined effort to compete.

“The fact that the race seems so close may very well throw North Carolina to the Obama camp, which I find astonishing,” said Duke University political expert Mike Munger, who also is a Libertarian candidate for governor. “We’re a Republican state in presidential elections.”

In Florida, Republican presidential candidate John McCain pulled 43 percent in the Zogby poll, with Obama at 40 percent. But Barr, a former Republican congressman from Georgia, pulled 3 percent.

“Florida has a tradition of some free thinkers,” said T. Wayne Bailey, political scientist at Stetson University in central Florida. “There’s some feeling that Barr might impact McCain. … The X-factor is that McCain has not fully brought to the base his genuine conservative credentials.”

Barr, noting his 11 percent showing in New Hampshire in the Zogby poll, explained his appeal. “Liberals who are tired of the Democratic Party acting as a doormat to the government’s assault against civil liberties,” he said, “and conservatives who are tired of the Republican Party’s reckless abandonment of fiscal responsibility are all potential Barr voters.”

However, Barr has problems with his base: He joined the Libertarian Party only a few years ago and won the nomination on the sixth ballot. In New Hampshire, Barr is still trying to get on the ballot by the Sept. 3 deadline; another Libertarian candidate, George Phillies, has already qualified, setting up the likelihood of two Libertarian presidential prospects on the ballot there.

“The majority of voters in New Hampshire are independents,” said Ken Blevens, the Libertarian U.S. Senate candidate in the Granite State. “They are fed up with the two-party system.”

Could they cost McCain the state in a close race? “Absolutely.”

Nader, who also will be on the New Hampshire ballot, was a factor there in 2000 when George W. Bush narrowly won the state.

“That’s one of the reasons people are so hostile to Nader,” said Nader New Hampshire coordinator Gary Hoffman. Still, he predicted that “a lot of independents are voting for Nader.”

According to a Time/CNN/ Opinion Research Corp. poll conducted from Aug. 24 to 26, “It’s clear that Ralph Nader could again have a significant impact on the presidential race – though in highly unpredictable ways.”

The poll found that in Nevada, Nader was the choice of 6 percent, yielding a McCain-Obama tie at 41 percent.

In New Mexico, where Nader polled 8 percent, he drew votes almost equally from both major candidates, while in Pennsylvania he drew more voters from McCain.

Nader’s antiwar, anticorporate message is resonating in some quarters. On the third day of the Democratic convention in Denver he held a rally attended by 4,000 and plans another on Thursday in Minnesota during the Republican convention in St. Paul.

Nader said that without participation in the three presidential debates, no third-party or independent candidate will get traction.

“So we could turn it into a three-way race, if we were really on those three presidential debates,” Nader said in a radio interview.