Midterm Seat Loss Averages 37 for Unpopular Presidents

The president's party almost always suffers a net loss of U.S. House seats in midterm elections. However, losses tend to be much steeper when the president is unpopular. In Gallup's polling history, presidents with job approval ratings below 50% have seen their party lose 37 House seats, on average, in midterm elections. That compares with an average loss of 14 seats when presidents had approval ratings above 50%.

History, then, is not on the Republicans' side this fall, as President Donald Trump has a 40% job approval rating two months before the 2018 midterm elections. With Republicans holding the White House and the majority of both houses of Congress, the lines of accountability are clear for voters who are unhappy with the state of the nation. Democrats need a net gain of 23 seats to take majority control of the House of Representatives.

For all midterm elections since 1946, the average midterm loss for the president's party is 25 U.S. House seats. Only two presidents, Bill Clinton and George W. Bush, saw their party gain seats in a midterm election. Both Clinton (66%) and Bush (63%) had high approval ratings just before those elections. Still, that popularity provided only enough boost to help their party pick up a handful of seats -- five for Clinton in 1998 and six for Bush in 2002.