Will third parties make a difference in November?

The Green Party of the United States chose its presidential candidate this month, nominating Dr. Jill Stein, a Harvard-educated physician and environmental activist from Lexington, Mass. Stein (in photo) defeated comedian and actress Roseanne Barr for the nomination and chose as her vice presidential running mate Cheri Honkala, an anti-poverty activist from Philadelphia, Pa.

Stein is the Green Party's first candidate to qualify for federal matching funds -- a boost for a third party that doesn't take corporate donations. While Ralph Nader ran for president as a Green Party candidate in 2000, he wasn't a party member, and when former U.S. Rep. Cynthia McKinney of Georgia ran for president as a Green in 2008 she didn't qualify for federal matching funds. So far Stein has qualified for those funds in the District of Columbia and 21 states, including Florida, North Carolina, Virginia and Texas.

Stein's qualification for federal matching funds is sparking questions about whether there could be a replay of the spoiler controversy in the 2000 presidential election, when many Democrats accused Nader of taking away enough votes from Al Gore in the hotly contested Florida race to tip the election to Republican George W. Bush.

But at this point polls suggest third-party candidates present little threat to either Democratic President Barack Obama or Republican challenger Mitt Romney. A Gallup poll conducted last month found that Libertarian Party presidential candidate Gary Johnson had the support of only 3 percent of registered U.S. voters, while Stein had only 1 percent. The paleoconservative Constitution Party's candidate Virgil Goode -- a former Virginia congressman who served variously as a conservative Democrat, independent and Republican -- polled at less than 0.5 percent nationally.

"The resulting data suggest 5% of U.S. voters could vote for a third-party candidate this year," Gallup observed -- though it acknowledged that number could rise if U.S. Rep. Ron Paul (R-Tex.) runs as an independent. But some Republicans worry that Goode could serve as a spoiler for Romney in what's expected to be a close race in Virginia, where a recent Public Policy Polling survey found Goode getting 9 percent of the vote in a three-way contest.

Stein, a former Lexington town meeting representative who ran unsuccessfully for several state offices, serves on the boards of Greater Boston Physicians for Social Responsibility and MassVoters for Fair Elections. She got experience debating Romney during their run for Massachusetts governor in 2002, when Stein received a 3.5 percent of the vote, which wasn't enough to affect the outcome.

Stein's platform calls for a "Green New Deal" to provide jobs at a living wage for every American willing and able to work, a transition to a sustainable economy through green technologies, a revamp of the financial sector, and expanding and strengthening U.S. democracy.

“Voting for either Wall Street candidate -- Romney or Obama -- just gives a mandate for four more years of corporate rule," Stein said in her acceptance speech at the party's convention in Baltimore earlier this month. "Every vote we receive is a vote for democracy, for the 99%, and for the survival of the planet."

The Green Party is currently on the ballot in 20 states and the District of Columbia, including eight of the 13 Southern states: Arkansas, Florida, Louisiana, Mississippi, South Carolina, Tennessee, Texas and West Virginia. The party is petitioning to get on the ballot in 19 other states, including Alabama, Kentucky, North Carolina and Virginia. Georgia is the only Southern state where the party is not on the ballot or petitioning for access yet. The Green Party has said it hopes to be on the ballot in 45 states in November.

The Libertarian Party -- the third-biggest party after the Democrats and Republicans -- made it on the ballot in all 50 states in 1980, 1982 and 1996, and is expected to do so again this year.

The South has not been a historic stronghold for the Greens, who have won the most popular support in the Pacific Coast, Upper Great Lakes and Northeast regions. For a chart showing party numbers as of January 2012 in the 29 states and District of Columbia where voters register by party, click here. In Florida, for example, there was a total of 11,241,022 registered voters as of January -- 40.5 percent Democrats, 36 percent Republicans, and 20.2 percent independents. Only 3 percent of Florida's voters are registered members of third parties, with Libertarians making up only 0.15 percent of all registered voters and Greens only .05 percent.

Among the problems facing Greens and other third parties are the restrictive ballot access laws in many states. In notoriously restrictive North Carolina, for example, a political party or independent candidate needs more than 80,000 signatures just to get on the ballot. The state Supreme Court upheld the state's tough ballot access requirements last year in a lawsuit brought by the Libertarian Party and joined by the N.C. Green Party, ruling that ballot access is not a fundamental right in a democracy.

The Constitution Party's Goode, who turned in his petitions to the N.C. Board of Elections yesterday in hopes of appearing on the ballot as a write-in candidate, recently told The News & Observer of Raleigh:

"North Carolina's harsh ballot access laws made it nearly impossible to get my name on the ballot. Therefore, I have petitioned to be a certified write-in for the State of North Carolina.''

Goode is formally on the ballot in 17 states and hopes to be an option in 40 in November.

On the other end of the spectrum from North Carolina is Louisiana, one of the easiest states for a presidential hopeful to get on the ballot. There recognized parties simply file their slate and access is automatic, while independent presidential candidates or candidates from non-recognized parties pay a fee of $500 or submit 5,000 signatures, with at least 500 from each congressional district.

Another challenge facing Stein and other third-party candidates is qualifying for inclusion in nationally televised presidential debates. In order to participate, the Commission on Presidential Debates requires constitutionally-eligible candidates to have achieved ballot access in enough states to at least theoretically be able to win an Electoral College majority in the general election and to have the support of at least 15 percent of the national electorate as determined by the averaged results of five national polling organizations.

Interestingly, at the same time third parties struggle for political legitimacy, the number of Americans who are not affiliated with either of the two major parties is growing. A recent Bloomberg News analysis found that the total number of independents in the key swing states of Colorado, Florida, Iowa, Nevada, New Hampshire and North Carolina grew by about 443,000 since the 2008 election.

In 2008, Obama captured 52 percent of the independent vote, while Sen. John McCain (R-Ariz.) got 44 percent.