In an advertisement for the Democrats in the USA in October, an image of the left-wing environmental politician Jill Stein is instantly transformed into the face of the Republican candidate and former President Donald Trump.

“A vote for Stein is actually a vote for Trump,” says a warning voiceover in the ad titled “Decisive.” The video cuts to Trump at a rally in Pennsylvania this year, saying: “Jill Stein? I like her very much. Do you know why? It takes 100 percent away from them.”

On October 28, the Democratic National Committee announced that it would spend about $500,000 at the last minute to persuade voters in swing states to support third-party candidates such as Stein, the Green Party's presidential candidate, and the independent candidates to vote candidate, Cornel West.

Both Trump and Democrats have suggested that Stein could hurt the votes of Democratic nominee and Vice President Kamala Harris and pave the way for a Trump victory.

But what do the surveys say? What impact could Stein, a third-party candidate, have on the outcome?

Who is Jill Stein and what are her key positions?

Stein, 74, is the US Green Party candidate for president. She announced her candidacy on November 9, 2023 via video message on X. She previously ran for the 2012 and 2016 elections.

Stein was born in Chicago and grew up in Illinois. She graduated from Harvard College in 1973 and Harvard Medical School in 1979. Her campaign website describes her as a practicing doctor.

The Greens are a left-wing coalition of green state parties in the USA that advocates for environmental protection and social justice.

Their positions on some of the key issues in this election are:

Israel's war against Gaza

Stein called for an immediate ceasefire in Gaza, an end to the blockade of the Palestinian enclave, the provision of humanitarian aid and the release of Palestinian prisoners in Israeli prisons as well as Israeli prisoners held in Gaza. According to her campaign website, she wants to “stop U.S. support and arms sales to human rights abusers.” She wants to “end the longstanding US practice of vetoing UN Security Council resolutions to hold Israel accountable to international law.” She also says she wants to dismantle NATO and “replace it with a modern, inclusive security framework that respects the security interests of all nations and people.”

War between Russia and Ukraine

The Greens do not want to further fuel the war between Russia and Ukraine and want to work for a peaceful end to the war.

Climate change

Stein's party wants to advance the Green New Deal proposal to transition to clean energy and achieve zero emissions. The party says it takes an “eco-socialist approach” to the environment that centers and compensates Black, Indigenous and poor people. Stein wants to declare a climate emergency and ensure the release of $650 billion a year to promote renewable energy and clean transport.

The economy

A Stein government would seek to create an economy that “works for working people, not just the rich and powerful.” Stein wants to introduce an economic bill of rights that would abolish private schools and guarantee free child care and a lifetime of free public education for everyone from preschool through graduate school. It also wants to forgive student debt for 43 million people in the United States. She also wants to cut taxes on incomes below the real average income of $75,000 per household and increase taxes on “the super-rich and giant corporations.”

How is Stein doing in the polls?

According to a New York Times poll released the first week of October, Stein was polling at about 1 percent nationally.

However, dissatisfaction is brewing among many Arab-American and Muslim voters with the two leading candidates – Harris and Trump – because of their steadfast support of Israel in the Gaza war.

The Council on American-Islamic Relations (CAIR), a US-based Muslim civil rights and advocacy organization, said on Friday that 42.3 percent of Muslim voters favor Stein, compared to 41 percent of Muslim voters who prefer Harris.

The survey of 1,449 verified Muslim American voters was conducted between October 1 and October 31. It found that only 9.8 percent of Muslim voters supported Trump.

As of February 27 of this year, CAIR estimated that there were approximately 2.5 million registered Muslim American voters. That's about 1.6 percent of the approximately 160 million registered voters in the USA.

How does Stein fare in the swing states?

Between October 30 and 31, Brazil-based analytics and data intelligence website AtlasIntel surveyed samples of voters in the seven swing states.

• Arizona: 1.1 percent of voters preferred Stein; 50.8 percent preferred Trump; and 45.9 Harris
• Georgia: 2 percent for stone; 48.8 percent for Trump; and 47.2 percent for Harris
• Michigan: 1.7 percent for stone; 49.2 percent for Trump; and 48.3 percent for Harris
• Nevada: 1.2 percent of voters chose “Other”; 50.5 percent chose Trump; and 46.9 percent chose Harris; Stein was not represented on the ballot
• North Carolina: 0.7 percent for stone; 50.7 percent for Trump; and 46.7 percent for Harris
• Pennsylvania: 1 percent for stone; 48.5 percent for Trump; and 47.4 percent for Harris
• Wisconsin: 0.8 percent for stone; 48.5 percent for Trump; and 48.2 percent for Harris

Could Stein influence this election?

Because the differences between Harris and Trump are so small, some experts believe votes for Stein could actually influence the election.

“The vote is so close right now that a small change in one direction or the other could swing it,” Bernard Tamas, a political science professor at Valdosta State University, told The Guardian newspaper.

The Guardian also quoted Nura Sediqe, assistant professor of American politics at Michigan State University, who said: “Muslims are divided. They don't all vote third parties, but let's imagine that there is a third party: Then you have up to 50,000 votes that traditionally went to the defecting Democrats. So if the margin is as narrow as it was last time, that could have an impact on the Democratic Party.”

On Friday, the European Green family, including green parties across Europe, released a joint statement calling on Stein to withdraw from the race and support Harris. “We are clear that Kamala Harris is the only candidate who can keep Donald Trump and his anti-democratic, authoritarian policies out of the White House,” the statement said.

However, Kyle Kopko, an associate professor of political science at Elizabethtown College in Pennsylvania, told Al Jazeera that while Stein could theoretically influence the election, in practice it depends on how close the election results are.

It would have to be an “extraordinarily close election” for her to win, said Kopko.

Have the votes for Stein ever swung in elections?

Stein ran in the 2016 election and won 132,000 votes in the battleground states of Wisconsin, Michigan and Pennsylvania. Together, the three states are worth 44 electoral votes.

Democrat Hilary Clinton lost in these three states by a combined 77,000 votes. Although Clinton won the popular vote, she lost the Electoral College vote to Trump, who received 304 votes compared to 227 votes for Clinton.

The Republican leader beat Clinton by a margin of 0.3 percentage points in Michigan, a margin of 0.7 percentage points in Pennsylvania and a margin of 0.7 percentage points in Wisconsin. These narrow victories gave him a total of 44 electoral votes from the three states.

In November 2016, an analysis cited by Vox suggested that if every Stein voter had voted for Clinton instead, she could have won Wisconsin, Michigan and Pennsylvania and thus the election.

However, Kopko said this could be misleading. If Stein had not voted, it is unlikely that every Stein voter would have voted for Clinton. “Some voters would become disillusioned and not vote at all or find another third-party candidate to vote for,” he said.

Did other third-party candidates influence the election result?

In the 2000 US presidential election, Green Party candidates Ralph Nader and Winona LaDuke ran on the party's ticket and ultimately won 2.7 percent of the vote. Nader got into the swing states of Florida and New Hampshire, and this is believed to have allowed the states to flip from Democratic to Republican.

This fueled speculation that the Green Party's candidacy was eating up Democrat Al Gore's share of the vote to ensure Republican George Bush's victory. The Greens denied this.

Gore won more than half a million votes and only conceded after a months-long legal battle.

The two-party political system has made it difficult for third parties to influence election results.

Since 1920, only four third-party candidates have won Electoral College votes. These are – Robert La Follette, who won 13 electoral votes in 1924; Strom Thurmond, who won 39 in 1948; George Wallace, who won 45 in 1968; and John Hospers, who won an electoral vote cast by an infidel voter in 1972.