Democrat Pat Ryan’s New York special election win is being called a bellwether. What does that actually mean?

Democrats’ surprising victory in a New York special election on Tuesday has many people asking if it’s a sign of what’s to come, and they’re citing a specific reason: The 19th Congressional District has voted for the president in the last three elections, making it a possible bellwether that reflects what voters are thinking elsewhere.

Democrats winning — or at least, not losing terribly — in the midterms represents a sharp reversal of fortune from just months ago, when inflation and President Joe Biden’s lagging approval rating led many to believe it would be a particularly tough election for the left. Democrats are facing a “nightmare,” “doomsday,” “bleak” scenario, news reports said. Now, with the New York results in, no one is so sure.

To better understand whether the election in New York’s 19th Congressional District is a sign of what’s to come, Grid spoke to two longtime pollsters about the nature of bellwether districts and what they can really tell us about elections: David Paleologos, director of the Suffolk University Political Research Center, and Spencer H. Kimball, director of Emerson College Polling.

What exactly is a bellwether district?

Bellwethers have been rapidly changing in recent years as the electorate shifts and parts of the country that used to be representative of American voters no longer are. But that doesn’t mean bellwethers aren’t useful, Paleologos said: You just need to know how to identify them.

The term generally refers to an area that swings to vote for the winning candidate in elections, but pollsters and politicos don’t have a shared technical definition.

To some, identifying bellwethers is a science: Paleologos uses his own proprietary method to parse districts each cycle and decide which areas are likely to determine the next election. His model has been accurate in predicting winners and losers 89 percent of the time, he said.

Paleologos puts potential bellwether districts through several “tests” to determine which he will use as bellwethers for an election. He looks at its voting history, runs a statistical analysis and weighs factors that change election to election, like the quality of the candidates running or the relevant news of the day — like the Supreme Court’s recent overturn of Roe v. Wade — that could motivate voters.

In Pennsylvania’s Senate race this year, for example, Republican Senate candidate Mehmet Oz is dragging in polls, significantly behind Democrat Senate candidate John Fetterman despite the favorable environment for Republicans — an indication the race would not be a good bellwether for Paleologos this year.

“There isn’t a silver-bullet, one-size-fits-all bellwether. You have to look at the particular election and the circumstances,” said Paleologos.

Was last night’s race in New York a bellwether for the midterms?

Democrat Pat Ryan’s victory in New York’s 19th Congressional District special election on Tuesday might be the latest signal that Democrats are faring better than they’d thought heading into the midterms, Paleologos and Kimball said.

The state’s 19th Congressional District swung to vote for the president in each of the last three elections, indicating a tendency for the district to act as a bellwether. But there are other factors at play that need to be considered, said Paleologos.

“It’s a district that gives us some indication — but I think you have to be measured” when drawing conclusions about Tuesday’s special election, said Paleologos. The issues that motivate voters in that district today might not be as relevant in November, for example.

Another consideration: Voters who show up for a special election may be different from the people who turn out in November. Still, said Kimball, special elections should be considered when trying to predict what might be ahead.

“Special elections prior to previous elections generally let you know if one party is gaining momentum. In 2017, a series of special elections showed where the electorate was going — then in the midterms the Democrats picked up 40 seats. In this example in New York’s 19th district, I don’t know if it’s a bellwether, but it is an indicator for the Democrats that they can compete in these districts.”

“I’m not sure this is going to forecast what’s to come,” he added, “but on the Republican side, I’d be concerned because this is a seat they were supposed to pick up.”

And what about states like Ohio? Do they deserve the bellwether status they’re given every four years?

The notion that, “As Ohio goes, so goes the nation,” was true for many years — but it won’t help predict the next election, Kimball said. The electorate has been changing in recent years, debunking many commonly-held beliefs about bellwether regions.

“A bellwether is a state that traditionally votes one way. Historically, Missouri used to be a bellwether state — they’d voted for the president in every election except once during the 1950′s, and then they blew it in 2012 and 2016,” Kimball said. Another example is Vigo County, Indiana, which had voted for every president in an election since 1956. The county’s streak ended in 2020 when it voted for Donald Trump over Joe Biden.

This shift is driven in no small part by the country’s changing demographics. Vigo was one of a series of bellwether counties — most of them with disproportionately white, less college-educated voters — that swung for Trump in 2020, ending their bellwether streaks. While these areas used to reflect the broader U.S. electorate well, that is no longer the case.

Demographic changes are just one of several factors that have made it particularly difficult to understand how voters will behave in recent years: Voters are more polarized now than in the past, districts have been redrawn via redistricting, and some people have moved homes during the covid pandemic.

“Over the last five years, there seems to have been more change than I can recall in the previous 20,” said Kimball.

Thanks to Alicia Benjamin for copy editing this article.