A bit of background... The 2024 Pennsylvania Senate race is expected to be one of the most closely watched contests of the election cycle. Analysts expect a highly competitive race, although Democratic incumbent Bob Casey Jr. has historically been a strong candidate. Pennsylvania's diverse electorate, with a mix of urban and rural voters, makes it a key swing state. The outcome of this race could have significant implications for the balance of power in the Senate.

The polling bias for the 2016 and 2020 Presidential elections is based on analysis from the American Association of Public Opinion Research (AAPOR) comparing actual results to national polls. For the 2018 and 2022 elections, bias was measured by comparing FiveThirtyEight's Generic Ballot polling average with the adjusted US House National Popular vote, using data from the UVA Center for Politics (2018) and DecisionDeskHQ (2022).