The United States electoral map consists of Democratic strongholds, like California, and red states that typically guarantee Republican wins, like Mississippi — along with a handful of swing states that could vote either way.

Winning these swing states is crucial for a presidential victory.

While candidates spend much of their time campaigning in these areas to secure a win, Andre Cire, an associate professor of operations management at Rotman, and his colleagues have discovered another way to increase the odds of turning these states red or blue: the relocation of a small number of partisan voters across state lines.

That number? Only tens of thousands across the country – a minor share of the 250 million eligible voters in the United States.

“The swing states are so [geographically] close to red and blue states … and it’s a winner-take-all system. If you win the state, you win the electoral votes of that state. That’s the key thing to understand,” says Cire.

In their paper, recently published in the INFORMS Journal on Computing, Cire and his colleagues developed a model which included historical voting data and 2024 election polling data. 

Before the 2024 election took place, they tested different scenarios to find out how many Democrat and Republican voters would need to relocate to swing states to increase the probability of their party winning the 2024 election. They tested the numbers incrementally, starting at 10,000 and moving up to 250,000 voters. They found that relocating 100,000 Democratic voters in blue states to swing states would have increased that party’s chances of winning by between 2.5 and 5.7 per cent. If 100,000 Republican voters in red states relocated to swing states, the Republicans’ chances of winning the election would have increased by between four per cent and nine per cent.

To swing an election, the model found that Republicans simply need to relocate to New Hampshire and Nevada, while Democrats should move to Pennsylvania, Nevada or North Carolina. Following the 2024 election, the researchers found that these critical states had the lowest margins of victory. 

Co-author Tallys Yunes, associate professor of management science at the Miami Herbert Business School at the University of Miami, was surprised that moving such a relatively small number of people could change a candidate’s probability of winning. He was also surprised that these voters didn’t have to move very far — only within 33 miles, or about 53 kilometres.

“If you live in a county that’s right at the [state] border, it’s almost like ‘I can move there for a month, continue to go to work, and that would have an effect,’” he says, noting that U.S. voting rules require a voter to live in the state for about 30 days to be eligible in that state. “I was surprised by the fact that not only the numbers are small, but the distance to move is super small as well.”

For example, in New Hampshire — a state President Trump won in 2024 by just under 23,000 votes — the paper notes that if 35,000 Republican voters moved from Massachusetts (a blue state), the Republican candidate’s likelihood of winning would have increased to 73.02 per cent, up from 24.71 per cent.   

Recognizing that asking party voters to pick up and move to a new state — even temporarily — might not sound feasible, Cire says it is within the realm of possibility.

“The distances are not too large (for people to move), and it may not be that expensive – especially depending on where you live,” says Cire, adding that moving might not be any more expensive than donating to campaigns for some highly motivated voters. 

For example, the authors’ paper points to a study that found the cost of moving from Lowell, Massachusetts to the nearby Nashua, New Hampshire (a roughly 30-minute drive away), was between $2,081 and $2,542 in August 2024. In comparison, more than 200,000 people donated more than $3,300 to the 2024 presidential election campaigns by August 2024. 

Cire says that the aim of the paper isn’t necessarily meant to provide actionable insights for those governing parties. Instead, the researchers wanted to raise awareness of a weakness that exists in the system.

“I don’t think someone would go and actively ask people to move — at least explicitly,” Cire says. “But if you think about it, there are migration patterns inside the U.S. and those migration patterns could be influenced one way or the other.”

“We felt it was important to bring this to the surface. We’ve already heard a lot about gerrymandering, which is people trying to unethically decide borders so that they favour a certain candidate,” Yunes adds. “This is yet another issue that people need to be careful and aware of.”