The modelers at FiveThirtyEight have made a compelling case that we should expect Republicans to pick up a seat or two in the upcoming U.S. Senate election. The purpose of this post is to show that this is essentially the same prediction we would have made two years ago, once we knew a Republican would be president at the midterm. …
In the interest of brevity, I am leaving aside the intellectual justifications for the two simple predictive models I will use here. The first model, the presidential partisanship model, predicts the net change in seats experienced by the president’s party at midterm by taking into account (1) the party of the president who won when the current class of senators was last elected and (2) the party of the president at midterm. The second model, the seats-at-risk model, substitutes the number of seats held by the incumbent president’s party for the party of the president who won the last time this class of senators were up for election. CONT.
Charles Stewart III (MIT), Election Update
