UB expert’s election forecasting model predicts big House gains for Dems

Democrats could gain as many as 44 seats and emerge from November’s mid-term elections with control in the House of Representatives, according to an innovative forecasting tool developed by a political scientist.

Republicans, meantime, are likely to pick up an additional two Senate seats and preserve their majority in the upper house of Congress.

“The midterm election’s outcome will play a major role in policy-making and the politics leading up to the presidential election of 2020,” says James Campbell, UB Distinguished Professor of Political Science and creator of the Seats-in-Trouble model.

Since 2010, Campbell, author of the recent book “Polarized: Making Sense of a Divided America” and an expert in campaigns and elections, has used his model to predict election outcomes with a high degree of accuracy.

“I’m approaching this scientifically in an attempt to get the best forecast,” says Campbell. “The model does not explain why there is partisan seat change, but explanation is not its purpose. It’s purely predictive.”

Campbell’s Seats-in-Trouble forecast for the 2018 congressional midterms will appear in a forthcoming issue of the journal PS: Political Science & Politics.

The Seats-in-Trouble model is distinct from related forecasts that rely mostly on either broad handicapping or national indicators such as the economy or presidential approval ratings. The Seats-in-Trouble model combines individual analysis by experts in each district, information provided by The Cook Political Report, with a statistical analysis of historical partisan seat change.

“That’s the model’s strength,” says Campbell. “It’s a hybrid that digs into the analysis right at the district level and pairs that with the historical record and how the two have matched up.”

Since the mid-1980s, The Cook Political Report has reported pre-election ratings of the competitiveness of congressional elections. The information has been publicly available on its website since 2008. Cook rates races for the Democrats and the Republicans as solid, likely, leaning toward the incumbent party or a toss-up.

Campbell’s debut model in 2010 predicted a Democratic loss in the House of 51 or 52 seats. The party actually lost an additional 12 seats, but seat losses that year were greater than at any time since the 1920s and no systematic forecast made before Labor Day that year was more accurate than Campbell’s.

The model did well two years later in predicting Democratic gains.

But Campbell, a devout Boston Red Sox fan who once wrote an article on the dead-ball era of congressional elections, began to hone his forecast to improve its batting average.

“When I first used The Cook Report’s archive, I counted a seat as ‘in trouble’ if it was currently held by a party and was considered ‘leaning’ or ‘a toss-up.’ That was too generous,” he says. “I needed a tighter definition of a seat-in-trouble. I think leaning districts are closer to being safe than they are closer to being toss-ups.”

Campbell’s predictions for the 2018 midterms align with the history, but he sees magnitude as the critical component when discussing partisan seat change.

“The president’s party routinely loses House seats in the midterms. That has been the case in all but three midterm elections since 1900,” he says. “Based on that history of seat changes, the real question is not which party will gain seats, but whether Democratic House seat gains this year will be small or large.”

When considering the congressional arithmetic for 2018, or what each party needs to hold or win a majority, Campbell says Democrats face a bigger challenge in the Senate.

“Democrats require only a two-seat gain for majority control. This seemingly small shift, however, is a tall order,” he says. “Democrats are defending many more seats than Republicans this year. They have to do well just to hold their current overall numbers.”