How predictive are generic ballot polls when it comes to forecasting the outcome of an election? In this week’s Political Edge, we review a new analysis on the predicative power of the generic ballot and look at what it will take for President Trump to win Pennsylvania in 2020.
The Predictive Power Of The Generic Ballot
In the 2018 midterm election, the congressional generic ballot question, which asks voters which party’s candidate they’d support for Congress (versus asking about a specific candidate), proved to be fairly predicative of the political environment. On election day last year, generic Democrats held an 8.7-point lead over generic Republicans. According to RealClearPolitics’ average, Democrats currently hold a 7.5-point lead. A 2017 analysis by FiveThirtyEight found that the “the generic congressional ballot is one of the most accurate predictors of who will get the most votes for Congress in a midterm election.”
Using the same methodology from 2017, FiveThirtyEight’s Nathaniel Rakich recently published an analysis looking at the predictive power of the generic ballot in presidential election years. Looking at generic polling averages on election day dating back to 1996, he found that they only missed by an average of two percentage points.
Rakich found that early generic-ballot polls more than a year before a presidential election also have some predictive power. Averaging polls from between January and June of the year before an election, Rakich demonstrates that “the national House popular vote in presidential cycles has usually wound up within a few points of those early polls.”
The analysis serves as a good reminder to keep an eye on how the generic vote is trending. As we get closer to election day, it could give analysts an idea of who may ultimately win control of the House.
Pennsylvania played a critical role in President Trump’s 2016 election and it’s almost assuredly to be a must-win state for him again in 2020. In fact, America First, the main super PAC supporting the president’s reelection campaign, has already announced a $300 million investment in six “must-win” states, which include Pennsylvania. So what will it take for the president capture the keystone state once again? The Philadelphia Inquirer dug into the numbers to find out.
Hold Onto Post-Industrial Counties And Rural Areas He Won In 2016: “Nationally, Trump has accelerated a political realignment: historically Democratic, small urban communities hit by economic change and rural areas shifting toward the Republicans, and traditionally Republican suburbs moving toward Democrats. Pennsylvania has seen both. Consider Erie County, one of the most drastic examples. Barack Obama easily won the county in the state’s northwest corner in 2012. Four years later, it turned narrowly red, thanks to a 21,000-vote swing toward Trump — nearly half of the margin that decided the entire state. The switch mirrored swings in other counties such as Luzerne, which saw a 32,000-vote shift toward the GOP compared to 2012, Lackawanna (23,000-vote shift), Northampton (11,000 votes) and Westmoreland (16,000), to name just a few.”
Mitigate The Democratic Suburb Surge: “If Trump changed the political landscape in smaller urban counties in 2016, he did the same in suburban ones — but there it shifted against him; Democrats see evidence that they have expanded on those gains… Consider Chester County, which narrowly supported Republican Mitt Romney in 2012, but gave Hillary Clinton a 26,000 vote edge in 2016. Two years later it elected a Democrat to Congress for the first time in recent memory, part of a wave that saw Democrats win almost every suburban congressional seat in the state….In Western Pennsylvania, Democrat Conor Lamb won a House seat in a district that Trump had won by 20 percentage points, thanks to a strong showing in previously red suburbs. His special election victory was backed up in 2018 by a win by state Sen. Pam Iovino who captured another longtime GOP seat in suburban Pittsburgh.”