It’s a near-certainty in American politics: the party holding the White House loses ground in midterm elections. The surge in turnout during presidential years gives the winner’s party a boost, but the ebb in midterm turnout typically costs that party seats in Congress.
Analysis of official House and Senate records from 1926 through 2022 shows that the president’s party has lost an average of 11.3 percent of its House seats and 6.7 percent of its Senate seats in midterms. Applied to the current landscape, that would mean Republicans lose 25 House seats and four Senate seats this November.
A Closer Look at Recent Trends
But the century-long average masks significant variability. Since 1986, the president’s party has fared better, losing only 9.2 percent of House seats and 5.8 percent of Senate seats. This improvement likely reflects more sophisticated gerrymandering that reduces competitive districts, as well as the exclusion of the volatile Great Depression and immediate postwar years from the sample.
Using the 1986–2022 trend, Republicans would lose 20 House seats and three Senate seats. A three-seat loss would produce a 50–50 Senate tie, leaving Vice President JD Vance’s tie-breaking vote to keep the GOP in control.
Second-Term Midterms: A Mixed Bag
Second-term midterms have their own pattern. Since 1986, the president’s party lost only 5 percent of House seats in second midterms but a steeper 10.7 percent of Senate seats. That would translate to just 11 House seats lost but six Senate seats lost for Republicans this year.
However, the sample is tiny—only four second-term midterms under Reagan, Clinton, George W. Bush, and Obama—and three administrations (George H.W. Bush, Trump, Biden) never had one. The Reagan and Clinton second midterms were outliers: Reagan lost just four House seats but eight Senate seats, while Clinton actually gained four House seats and lost none in the Senate. By contrast, Obama and George W. Bush saw their parties lose an average of 10 percent of House seats and 14 percent of Senate seats.
Redistricting Could Shift the Balance
Mid-decade redistricting adds another variable. Several states have redrawn maps, with some still under legal challenge. Democrats are projected to gain six seats in California and Utah, while Republicans could pick up as many as 16 seats in states like South Carolina, Florida, Louisiana, Missouri, North Carolina, Ohio, Tennessee, and Texas.
If those projections hold, Republicans could net eight or more House seats. That might not sound like much, but with the president’s party losing a smaller percentage of seats in recent midterms, those gains could be decisive. Based on the Obama–Bush second-term average, Republicans would lose 21 House seats; factoring in redistricting gains could put them within striking distance of keeping their slim majority. The ongoing GOP infighting over reconciliation could complicate their ability to hold the line, however.
Senate Math: Tougher but Not Hopeless
The Senate is harder to predict because only a third of the chamber is up every two years, and the map rarely favors one party heavily. This year, 35 seats are in play—including special elections in Florida and Ohio—and Republicans are defending 22 of them. While Democrats have a numerical advantage, truly flippable seats are limited: Georgia, New Hampshire, and Michigan for the GOP; Maine, North Carolina, Ohio, and Texas for Democrats.
Even if Democrats swept all those races, the GOP would lose four seats, a 7.5 percent loss. That’s below the 10.7 percent average for second midterms since 1986 and just above the overall 5.8 percent average loss for that period. In other words, the Senate picture is consistent with historical norms, and if Democrats don’t take all the competitive seats, Republicans will outperform past midterms.
What the Numbers Mean for November
The historical record provides a range of outcomes, not a single prediction. The long-term trend still points to losses for the president’s party, but the more muted pattern of recent decades may hold. The second-midterm factor could cut either way, depending on whether the result mirrors the Reagan–Clinton or Bush–Obama experience.
One wild card is the surge of independents to 47 percent of the electorate, which could reshape traditional partisan dynamics. Another is the impact of policy debates: the Senate Democrats’ new drug pricing plan aims to counter the White House’s messaging advantage. Ultimately, the midterms will test whether American politics is becoming more volatile or whether the lower-volatility trend of the last four decades will persist. For Republicans, the historical math offers a fighting chance, but the margin for error is razor-thin.
