How swing states came to be critical in U.S. presidential elections

Richardson is a swing voter in a swing state; those few jurisdictions that sometimes vote Republican, sometimes vote Democratic and have the power to influence the results of national elections.

Most states consistently vote red or blue — between 2000 and 2016, 38 states voted for the same political party — but swing states are less predictable.

Political campaigns and pundits have long focused on states such as Pennsylvania because they offer candidates an opportunity to sway voters off the fence and win coveted Electoral College votes. In recent years, they’ve also had the power to swing the election itself.

Campaign signs at an intersection near a voting station in November 2020, in Pahrump, Nev. (Ronda Churchill/AFP via Getty Images)

“Swing states have increasingly become not just states that flip back and forth, but states, given the relative polarization and certainty of other states voting particular ways, these are the small cluster of states that truly are going to decide the presidential election,” said David Schultz, a professor of political science and legal studies at Hamline University and editor of Presidential Swing States: Why Only Ten Matter.

What are swing states, anyway? How did so much political power come to be concentrated in just a few states? And is it fair?

It all starts with the Electoral College

The only reason the concept of a swing state exists at all is because of the unique way the U.S. conducts presidential elections: with the Electoral College.

The U.S. doesn’t elect presidents based on the national popular vote. “It’s essentially 50 separate state elections plus the District of Columbia,” Schultz said. (In fact, two presidents have been elected in recent decades even though they lost the national popular vote — George W. Bush in 2000 and Trump in 2016.)

After the election results are in, people known as electors, appointed by all 50 states and the District of Columbia, send their votes for president and vice president to Congress based on the results of the vote tally in their jurisdiction.

Maine and Nebraska assign their electors proportionally, but the other 48 states and the District of Columbia have a winner-take-all system, meaning they assign all their electors to the candidate who wins a majority of the vote.

In most of the country, a candidate who wins a state by even a slim margin gets all of that state’s electoral votes. The 2000 presidential election between Bush and Democrat Al Gore came down to a difference of just 537 votes in one swing state, Florida.

According to Schultz, this is not what the Framers had in mind when they created a system they hoped would prevent larger states from having an unfair advantage in national elections.

A man walks into an early voting location in October 2020 in Fayetteville, N.C. (Alex Wong/Getty Images)

“The idea was that the Electoral College would prevent small states from being overlooked,” he said. “But … what we know is for at least 150 years, maybe even longer, that there are some states that are really decisive in the election.”

What is a swing state, anyway?

According to Schultz, four different criteria determine a swing state:

First, the state is a battleground. Presidential candidates and their campaigns visit these places often to stump for votes between Memorial Day and Labor Day.

Second, it’s a competitive state. For Schultz, that means the margin of victory for the winning presidential candidate has been less than 5% of the vote.

Third, this state would be considered a bellwether. In past elections, the candidate who won the state has gone on to win the presidency. Some states have been good predictors of who would ultimately end up in the White House.

Fourth is the so-called flippability factor. Does this state see-saw between political parties? For example, Pennsylvania went for Obama in 2012, Trump in 2016 and Biden in 2020.

Even within swing states, not every voter is a swing voter. Schultz suggests that this year’s presidential contest could hinge not simply on swing states but swing counties. He estimates that 5% of the voters in five counties in five states could determine the outcome of this year’s contest.

“For me, this presidential campaign is coming down to maybe 150,000 voters that are decisive,” Schultz said.

NPR has reported that Pennsylvania, North Carolina, Georgia, Michigan, Arizona, Wisconsin and Nevada will be the states to watch this fall.

Why do some states swing — and others don’t?

Swing states don’t necessarily stay swing states forever, and other consistent performers can turn into toss-ups. Arizona only became a swing state recently, while longtime swing states such as Florida and Ohio have gone reliably Republican.

Political experts say many factors can help transform a state into a swing state or turn a swing state solidly blue or red.

For example, increased political polarization is hardening partisan divides across the country.

Also, the movement of people around the U.S. for jobs, retirement and other reasons can cause demographic shifts — including fluctuations in a state’s racial and ethnic makeup — that can alter the area’s political fabric. Immigration may also play a role.

A poll worker lays out stickers at the Gwinnett County Fairgrounds in October 2020 in Lawrenceville, Ga. (Justin Sullivan/Getty Images)

“That’s an interesting part of the puzzle, the migration patterns,” said David Damore, a University of Nevada, Las Vegas professor of political science and coauthor of Blue Metros, Red States: The Shifting Urban/Rural Divide in America’s Swing States. “When blue state voters leave, where do they go? Do they bring their blue state politics?”

Additionally, Damore noted that social issues are largely replacing economic differences and driving the political conversation in swing states. He cited several examples, including North Carolina’s transgender bathroom bill in 2016 and Georgia’s “fetal heartbeat” abortion law in 2019.

“Right now, what’s become the sort of battleground is those second- and first-ring suburbs around the urban cores that used to be much more reliably Republican,” he said. “But because of the shifting agenda and the emphasis on social issues, that has become certainly quite ripe for Democrats.”

How swing states influence national politics

Because swing states are so important to the outcome of a presidential election, campaigns tend to spend a lot of money and time there.

“It has huge implications for how resources get deployed,” Damore said. “If you’re in California, you really don’t see a presidential election. You come to Nevada, you can’t escape it.”

The power of swing states can also dampen voter turnout in other parts of the U.S. where partisan majorities are stronger and people feel like their vote may not matter. If you know your state is going to go Republican, why vote for the Democrat, the thinking goes.

Severalstudies have even suggested that politically crucial swing states may get some additional federal resources.

For Schultz, the outsize sway held by swing states, a power they derive from the Electoral College, has made presidential elections less fair, especially to voters in non-swing states across the U.S. hoping to have their voices heard.

“Even though the concept of ‘one person one vote’ is supposed to apply when it comes to presidential elections, ‘one person one vote’ does not mean equal influence,” he said. “Some votes effectively matter more than others.”

There have been attempts at change. An effort to circumvent the Electoral College, called the National Popular Vote Interstate Compact, would see states assign all of their electors to the winner of the national popular vote rather than the winner of that state. Though it wouldn’t eliminate the Electoral College, it would have the effect of electing a president based on the popular vote. Seventeen states and the District of Columbia have enacted the idea into law.