Senate - 9/30/24

Ohio: Poll Weighting Discrepancy: The Ohio Senate race is getting closer, but a comparison of why we see different polling margins of the same race from studies conducted during a similar sampling period relates to data weighting methodology.

A comparison of how two recent Ohio pollsters weighted their data was made evident when looking at the New York Times/Siena College formula versus that of PollFair. According to NYT/Siena, the Ohio partisan formula breaks 29% D, 34% R, 36% I, which translates into a R+5 advantage. PollFair, however, weights the same electorate differently: 31% D, 39% R, 30% I, which would yield a R+8 GOP advantage. It is these types of statistical calculations that largely account for most polling discrepancies.

RCP Ratings: 4 of 6 Rated Toss-Ups Are Not: The Real Clear Politics US Senate rating chart is making the Toss-Up category too widespread. In fact, four of the six rated Toss-Ups campaigns should be in other categories.

The six that RCP rates as Toss-Ups are the Arizona and Michigan open races, and the incumbent contests for Sens. Rick Scott (R-FL), Sherrod Brown (D-OH), Bob Casey, Jr. (D-PA), and Tammy Baldwin (D-WI). 

The only races where the empirical and financial data could conceivably support a Toss-Up rating are the Michigan and Ohio races, and even they at least tilt toward the Democratic candidate. For the Arizona, Scott, Casey, and Baldwin campaigns, it appears the recent polling data, resource imbalance, and historical voter performance have not been given proper consideration. 

Accounting for the strong GOP gains in Florida over the past few years, the Scott race should be in the Lean Republican column. There is no data to suggest that Sens. Casey and Baldwin should not be considered favorites for re-election, and Rep. Gallego has enjoyed a clear lead in the Arizona race since the beginning of the general election cycle. All four should be in the Lean Democratic column.