The president's party has lost seats in the House of Representatives in every midterm election since 1934 except three. The size of the loss tracks the president's approval rating and the generic ballot; the direction almost never changes. The Senate, with only a third of seats contested, is far less predictable.
President Clinton's approval was in the low 40s and the generic ballot favoured Republicans.
What happened next: Democrats lost 54 House seats and 8 Senate seats, and Republicans took the House for the first time in forty years.wave loss
President Clinton's approval was above 60% during the impeachment process and the economy was booming.
What happened next: Democrats gained 5 House seats, one of three midterm gains for a president's party since 1934.gain
President Bush's approval was above 60% a year after the September 11 attacks.
What happened next: Republicans gained 8 House seats and 2 Senate seats.gain
President Bush's approval was in the high 30s amid the Iraq war and Hurricane Katrina.
What happened next: Republicans lost 30 House seats and 6 Senate seats, and Democrats took both chambers.wave loss
President Obama's approval was in the mid 40s after the financial crisis and the health-care law.
What happened next: Democrats lost 63 House seats, the largest midterm loss since 1938, and 6 Senate seats.wave loss
Approval in the low 40s and low turnout.
What happened next: Democrats lost 13 House seats and 9 Senate seats, handing Republicans the Senate.modest loss
President Trump's approval was in the low 40s and Democrats led the generic ballot by about eight points.
What happened next: Republicans lost 40 House seats, and Democrats took the House, while Republicans gained 2 Senate seats on a favourable map.wave loss
President Biden's approval was in the low 40s with inflation at a forty-year high, and a red wave was widely forecast.
What happened next: Democrats lost only 9 House seats, enough to lose the chamber narrowly, and gained a Senate seat.modest loss
Share of the 8 cases above that resolved this way. Small samples: treat as a prior, not a forecast.
Sabato's Crystal Ball rates 225 House seats at least lean Democratic, prediction markets put Democrats at 91% for the House and 65% for the Senate, and Trump calls the polls fake. Since 1934 the president's party has lost House seats in 20 of 23 midterms.
