CHARLOTTE, N.C. (AP) -- It's lunchtime, and Mary Goode is leaning toward voting for Republican John McCain. By dinner, she admits she might be for Democrat Barack Obama.
But there's no chance that on Election Day she will be for any candidate from a third party.
"This election is too important," said Goode, a 43-year-old accountant from Charlotte. "That would just be like throwing my vote away. I'm not going to do that."
Without billionaire H. Ross Perot and his flip charts, Bill Clinton might not have won the White House in 1992. If Ralph Nader hadn't won 32,000 votes in Florida, Al Gore might have moved into the Oval Office in 2000.
But this year, neither Nader, former GOP Rep. Bob Barr - running as a Libertarian - or any of the other small-party candidates who have qualified for the ballot in some states appears likely to play the role of spoiler.
"In some sense, there are some purists who say you have to vote for what's right. You just can't vote for the lesser of two evils," said Dennis Goldford, a political science professor at Drake University in Iowa.
"But with the economy in the situation it's in, I don't think people feel like they have the luxury of just shopping around. They're saying: 'Somebody has to fix this in a hurry and you know it's not going to be one of these third-party guys.'"
There is a long history of third-party candidates in presidential politics, but few that could be called a success. Among those that connected with voters are two relics of racial politics: Strom Thurmond won 39 electoral votes in 1948 on the States' Rights Democrats ticket and Alabama Gov. George Wallace's 1968 bid on the American Independent ticket captured 46 electoral votes.
"Since 1832 - the birth of the modern Democratic Party - only 13 times has a third-party candidate actually pulled better than 5 percent of the vote," Goldford said. "So as much as people complain about the two major parties, people tend to vote overwhelmingly for them."
Third-party candidates can affect the outcome.
While he did not win any electoral votes in 1992, Perot won 19 percent of the popular vote and helped push Clinton into office. Nader did not come close to Perot's level of support in 2000, but because it came disproportionately from voters who were otherwise likely to vote for Gore, it was enough to swing the outcome of a tight race to George W. Bush.
"It would have made a difference in Florida and New Hampshire," said Charles Prysby, a political science professor at the University of North Carolina at Greensboro. "If Nader had not been on the ballot anywhere, his 2.7 percent - a lion's share would have gone to Gore. And that would have put him over the top in those two states."
So is there any chance of that this year? Probably not.
Barr is on the ballot in the six states that are viewed as tossups heading into Election Day: North Carolina, Florida, Indiana, Missouri, Nevada and Ohio, worth a total of 89 electoral votes. Nader is on the ballot in four of them, and is eligible as a write-in candidate in North Carolina and Indiana.
But neither registers any significant support in recent polls conducted in those states. And unlike past third-party candidates who did well at the ballot box, neither Barr nor Nader are charismatic campaigners focused on a single issue.
"Do they represent a particular section of the country at this point? No. Have they managed to capture great popular discontent on a particular issue. No," Goldford said. "There's nothing particular that Barr or Nader is saying that resonates with these folks."
Barr, a former Georgia congressman, is polling around 4 percentage points in his home state. That could give Obama a chance against McCain in the recently reliable Republican state, but if the Illinois senator wins there, it is almost sure to be part of a nationwide landslide and not a 2000-style squeaker.
Paul Davidson, 53, a retired police officer from Charlotte, said he tried to read up on all the candidates - including Barr. But in the end, he plans to vote for McCain.
"I think it's great you have all these people running. That's what America is all about," Davidson said. "But you have to think long and hard about how you're going to vote. I like Barr, but McCain needs every vote he can get to beat Obama."