I have written a couple of articles here about the net difference by party in the number of Representatives retiring from the House. I found a relatively strong relationship between retirements and the number of seats won or loss in off-year elections, but I found no relationship between the two measures in Presidential years.
These two charts tell the basic story. On the left we have the relationship for off-year elections, where changes in the number of Republican retirements correlate with the number of House seats won or lost in each election. The chart on the right presents the same measures for Presidential years. In off-year elections, the number of Republican seats won or lost depends to a degree on the difference between the number of Republicans and Democrats retiring from the House. In years like 1958 and 2018, relatively large numbers of Republicans left the House, and the party lost seats overall.
The chart on the right shows there was no systematic relationship between retirements and House results in election years dating back to 1936 when the President is on the ballot. However before we jump to the conclusion that retirements will again not be predictive in 2020, a closer look is in order.
This year 28 Republicans (counting Justin Amash) have relinquished their seats in the House of Representatives compared to nine Democrats. This difference of +19 in net Republican retirements is the second-largest number recorded for an on-year election since the New Deal, just behind the value for 2008. In that year there were 21 net Republican retirements, and the party lost 24 seats. Only the 1964 landslide election between Johnson and Goldwater saw more Republican seat losses. Might the 2008 result be a bellwether for the result in 2020?
Using the ratings at the Cook Political Report we find two open seats in the “likely Republican” category, three in the “lean Republican” category, and five more seats considered Republican “toss-ups.” For the Democrats, two open seats fall into the “likely Democratic” category, one in the “lean Democratic” group, and just one more is considered a toss-up. Overall we have eight Republican seats in the lean/toss-up categories compared to just two Democrats.
Having as many as 19 retirements from the President’s party in a year when he is running for re-election is extremely rare. Since 1948, net retirements in years when the President is on the ballot averaged just 3.6 (both Democrats and Republicans), reaching a maximum of seven in 1996. That makes it difficult to evaluate the meaning of this year’s net departure of nineteen Republicans. Perhaps we may not see a “blue wave” result like 2008, with its 21 net Republican retirements and a net loss of 24 GOP seats. But it wouldn’t be surprising to see the Democrats pick up some eight to ten House seats in November.
