In an advertisement for the Democrats in the United States in October, an image of left-wing environmentalist politician Jill Stein morphs into the face of Republican candidate and former President Donald Trump within the blink of an eye.

“A vote for Stein is really a vote for Trump,” a cautionary voiceover in the advertisement, titled “Crucial”, says. The video segues into Trump at a Pennsylvania rally this year, saying: “Jill Stein? I like her very much. You know why? She takes 100 percent from them.”

On October 28, the Democratic National Committee announced that it would spend about $500,000 in a last-minute effort to persuade voters in swing states against voting for third-party candidates such as Stein, the Green Party’s nominee for the presidential election, and the unaffiliated candidate, Cornel West.

Both Trump and the Democrats have implied that Stein could dent the vote for Democratic candidate and Vice President Kamala Harris, paving the way for a Trump win.

But what do the polls say? How much 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 nominee for the presidential election. She announced her candidacy via a video message on X on November 9, 2023. She previously ran for the 2012 and 2016 elections.

Born in Chicago and raised in Illinois, Stein graduated from Harvard College in 1973 and from Harvard Medical School in 1979. Her campaign website describes her as a practising physician.

The Green Party is a left-wing federation of Green state parties in the US, advocating for environmentalism and social justice.

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

Israel’s war on Gaza

Stein has 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 jails alongside Israeli captives being held in Gaza. According to her campaign website, she wants to “stop US 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 disband NATO and “replace it with a modern, inclusive security framework that respects the security interests of all nations and people”.

Russia-Ukraine war

The Green Party wants to “stop fuelling” the Russia-Ukraine war and work on negotiating a peaceful end to it.

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” towards the environment, centring and compensating Black people, Indigenous people and the poor. Stein wants to declare a climate emergency and ensure the release of $650bn annually to boost renewable energy and clean transport.

The economy 

A Stein administration would seek to create an economy that “works for working people, not just the wealthy and powerful”. Stein wants to introduce an economic bill of rights, abolishing private schools and guaranteeing free childcare and a lifelong free public education for all from preschool to graduate school. Additionally, she wants to cancel student debt for 43 million people in the US. She also wants to reduce taxes on incomes below the real median income of $75,000 per household, and increase taxes on “the ultra-wealthy and giant corporations”.

How is Stein faring in the polls?

Overall, Stein was polling at about 1 percent nationally, according to The New York Times polling released in the first week of October.

However, discontent is brewing among many Arab-American and Muslim voters towards both the leading candidates – Harris and Trump – because of their unwavering support for Israel in its war in Gaza.

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

The poll of 1,449 verified Muslim American voters was conducted between October 1 and 31. It showed just 9.8 percent of Muslim voters were in support of Trump.

On February 27 this year, CAIR estimated that there were about 2.5 million registered Muslim American voters. That is approximately 1.6 percent of some 160 million registered voters in the US.

How is Stein polling in the swing states?

Between October 30 and 31, Brazil-based analytics and data intelligence website AtlasIntel polled 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 Stein; 48.8 percent for Trump; and 47.2 percent for Harris

Michigan: 1.7 percent for Stein; 49.2 percent for Trump; and 48.3 percent for Harris

Nevada: 1.2 percent of voters chose “Others”; 50.5 percent chose Trump; and 46.9 percent chose Harris; Stein did not figure on the ballot

North Carolina: 0.7 percent for Stein; 50.7 percent for Trump; and 46.7 percent for Harris

Pennsylvania: 1 percent for Stein; 48.5 percent for Trump; and 47.4 percent for Harris

Wisconsin: 0.8 percent for Stein; 48.5 percent for Trump; and 48.2 percent for Harris

Could Stein swing this election?

As the margins between Harris and Trump are so slim, some experts believe that votes for Stein could indeed swing the election.

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

The Guardian also quoted Nura Sediqe, an assistant professor in American politics at Michigan State University, who said: “Muslims are split. They’re not all voting third party, but let’s imagine a third are: then you’ve got up to 50,000 votes that had traditionally gone to the Democrats moving away. So if the margin is as slim as it was last time, it may affect the Democratic party.”

On Friday, the European Green family, including Green parties all over Europe, released a joint statement calling on Stein to withdraw from the race and endorse Harris. “We are clear that Kamala Harris is the only candidate who can block Donald Trump and his anti-democratic, authoritarian policies from the White House,” the statement read.

However, Kyle Kopko, an adjunct professor of political science at Elizabethtown College in Pennsylvania told Al Jazeera that while Stein can, in theory, swing the election, in practise it depends on how close the election results are.

It will have to be an “extraordinarily close election” for her to swing the vote, Kopko said.

Have votes for Stein swung elections before?

Stein contested the 2016 election and won 132,000 votes across battleground states Wisconsin, Michigan and Pennsylvania. Together, the three states are worth 44 Electoral votes.

In these three states, Democrat Hilary Clinton lost by a combined 77,000 votes. Despite winning the popular vote, therefore, Clinton lost the Electoral College vote to Trump, who won 304 votes compared with Clinton’s 227.

The Republican leader beat Clinton in Michigan with a 0.3 percentage point margin of victory, in Pennsylvania with a 0.7 point margin of victory and in Wisconsin with a 0.7 point margin. These narrow victories earned him 44 Electoral votes combined 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 therefore, the election.

Kopko said this might be misleading, however. If Stein had not been on the ballot, it is unlikely that every Stein voter would have voted for Clinton. “Some voters would be disillusioned and not vote at all, or find another third party candidate to vote for,” he said.

Have other third-party candidates affected election results?

In the 2000 US presidential election, Green Party candidates Ralph Nader and Winona LaDuke contested the election on the party’s ticket and ended up winning 2.7 percent of the popular vote. Nader made inroads in swing states Florida and New Hampshire, and it is believed that this allowed the states to switch from the Democrats to the Republicans.

This fed speculation that the Green Party ticket ate away the vote share for Democrat Al Gore to bolster a Republican George Bush win. The Green Party denied this.

Gore won more than half a million votes and conceded only after a monthlong legal battle.

The two-party political system has made it difficult for third parties to make a dent in election results.

Only four third-party candidates have been able to win Electoral College votes since 1920. They 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 one Electoral vote cast by a faithless elector in 1972.