Congress primary election upsets have already changed the 2026 midterm field, with longtime incumbents losing party nominations and unexpected candidates emerging in key House and Senate contests. The latest results from Michigan, Tennessee, Missouri and Hawaii have added to a season marked by major challenges from both the Republican and Democratic sides.
The primary contests have produced several notable defeats. Republican incumbents such as John Cornyn, Thomas Massie, Dan Crenshaw, Bill Cassidy and Andy Ogles have lost their bids for another term. Democrats have also faced major setbacks, including Shri Thanedar, Al Green, Adriano Espaillat, Dan Goldman and former Rep. Cori Bush.
These results have created a different congressional landscape heading toward November. Some races were driven by ideological battles. Others were shaped by redistricting, local political changes or strong challengers who built enough support to overcome established incumbents.
The results also show that congressional seniority does not guarantee another nomination. Primary voters in several states have demonstrated a willingness to replace familiar names with candidates offering a different political direction.
Bill Cassidy’s defeat became an early Republican shock
One of the most important Republican primary defeats came in Louisiana, where Sen. Bill Cassidy failed to advance from the Republican Senate primary.
Cassidy finished third in the May 16 contest. U.S. Rep. Julia Letlow placed first, while former Rep. John Fleming finished second. Cassidy’s result ended his campaign for another Senate term.
The defeat carried particular significance because Cassidy was a sitting senator with extensive experience in Washington. His political relationship with President Donald Trump had also become a major issue.
Cassidy voted to convict Trump during the Senate impeachment trial following the January 6 attack on the U.S. Capitol. Trump later backed Letlow in the Louisiana Republican contest.
Letlow eventually won the Republican nomination in the runoff and moved forward to the general election.
The Louisiana result established an important pattern for the 2026 primary season. A sitting member’s record in Congress could become a disadvantage if primary voters viewed the incumbent as insufficiently aligned with the party’s current direction.
John Cornyn’s Texas defeat changed the Senate race
Texas produced another major Republican upset when Sen. John Cornyn lost the Republican runoff to Attorney General Ken Paxton.
Cornyn had served four terms in the Senate and was one of the most established Republican figures in Washington. His defeat marked a significant change for the Texas Senate race.
Paxton defeated Cornyn by a wide margin in the May runoff. The result gave Republicans a nominee with a very different political profile from the longtime senator.
Cornyn’s loss was closely watched because Texas remains one of the country’s most important Republican states. A competitive primary there can attract national attention because the Republican nominee is generally favored in the November election.
The contest also demonstrated the importance of primary voters in states where one party has a strong advantage. In such situations, the primary can effectively determine which candidate will represent the state in the next Congress.
Thomas Massie lost after a major Republican challenge
Kentucky Rep. Thomas Massie became another high-profile Republican incumbent to fall in the primary.
Massie had developed a reputation for breaking with Republican leaders and President Trump on selected issues. That independence helped establish his national profile but also made him a target among Republican activists who wanted a different representative.
Navy veteran Ed Gallrein challenged Massie and defeated him in the Republican primary.
Trump supported Gallrein during the contest, adding national attention to the race.
Massie’s defeat was especially notable because he had repeatedly won reelection in the heavily Republican district. His primary loss demonstrated that an established House member can still face serious pressure when party activists become dissatisfied with the incumbent.
Gallrein now moves into the general-election campaign with the Republican nomination.
Dan Crenshaw’s primary defeat added to the Texas shakeup
Texas produced another major House upset when Rep. Dan Crenshaw lost the Republican primary in the 2nd Congressional District.
Crenshaw had represented the Houston-area district since 2019. His military background and national media presence made him one of the better-known Republican House members.
State Rep. Steve Toth defeated Crenshaw in the primary.
The race reflected divisions within the Texas Republican Party over the direction of the congressional delegation. Crenshaw had developed a reputation as a more independent Republican on certain issues, while Toth campaigned as a conservative alternative.
The result removed another incumbent from the November ballot and added to the number of Republican House seats entering the general election with new nominees.
Democratic incumbents also faced major primary losses
The 2026 primary season has not been limited to Republican defeats.
Democrats have experienced several significant incumbent losses, particularly in New York, Texas and Michigan.
In New York, Rep. Adriano Espaillat lost the Democratic primary in the 13th Congressional District. Espaillat had represented the district since 2017 and held a prominent position within the House Democratic caucus.
Darializa Avila Chevalier defeated Espaillat, giving Democrats a new nominee for the district.
Rep. Dan Goldman also lost his Democratic primary in New York. Former New York City Comptroller Brad Lander defeated Goldman in the 10th Congressional District.
Goldman’s defeat was one of the clearest Democratic incumbent losses of the season. He had served two terms in Congress, but Lander built enough support to remove him from the November ballot.
The two New York contests demonstrated that Democratic incumbents could face strong primary challenges even in districts where the party has a major electoral advantage.
Al Green’s long congressional career ended in Texas
Texas Democrat Al Green also lost his primary after redistricting changed the political environment around his seat.
Green had served in Congress for more than two decades. He faced state lawmaker Christian Menefee in the Democratic runoff after the two candidates emerged from the initial primary.
Menefee defeated Green by a substantial margin.
The redrawn district played an important role in the contest. Green was no longer running in the same congressional district that had supported him for many years.
Redistricting can create unusual situations for incumbents. A lawmaker may retain the title of incumbent while suddenly representing a district with many voters who have never previously voted for them.
Green’s defeat shows how changes to congressional boundaries can make even long-held seats politically uncertain during primary season.
Read More – Congressman Andy Ogles Loses Republican Primary in Tennessee Upset
Michigan produced two of the newest House surprises
Michigan’s August 4 primary brought another important group of results.
Democratic Rep. Shri Thanedar lost the Democratic primary in the 13th Congressional District to state Rep. Donavan McKinney.
Thanedar had won the seat in 2022 and was seeking another term. McKinney defeated him in the Democratic contest and will now represent the party in November.
The race attracted attention because the district is centered around Detroit and has a long history of Democratic representation.
McKinney’s victory also carried a strong local representation issue. His campaign emphasized Detroit’s political identity and the importance of having representation connected to the communities within the district.
Because the district strongly favors Democrats, winning the primary placed McKinney in a strong position for the general election.
A suspended candidate unexpectedly won in Michigan
The Republican primary in Michigan’s 8th Congressional District produced one of the most unusual outcomes of the 2026 election cycle.
Thomas J. Smith won the Republican nomination even though he had suspended his campaign before Election Day.
Smith withdrew from active campaigning in July and endorsed another candidate. His name nevertheless remained on the ballot.
When voters cast their ballots, Smith won the Republican nomination.
He defeated Amir Hassan, a Navy veteran who had received Trump’s endorsement and entered the contest with significant political backing.
The result immediately became one of the most unexpected congressional primary stories of the year.
Smith’s victory illustrates the importance of ballot status in primary elections. Once a candidate’s name remains on the ballot, voters can still select that candidate even if the campaign has stopped operating.
The Michigan result also showed that endorsements do not automatically determine primary outcomes.
Andy Ogles lost after Tennessee redistricting
Tennessee Rep. Andy Ogles became another Republican incumbent defeated in the August primary.
Former Tennessee Agriculture Commissioner Charlie Hatcher defeated Ogles in the Republican primary for the state’s newly drawn 5th Congressional District.
Ogles had received Trump’s endorsement, but that support did not prevent his defeat.
The new congressional map significantly changed the district. A large share of the voters in the newly drawn district had not previously been part of Ogles’ old congressional constituency.
That created a different electorate and forced Ogles to introduce himself to many voters who had not previously been represented by him.
Hatcher’s victory therefore combined an incumbent challenge with the effects of redistricting.
The result is another reminder that congressional maps can dramatically alter the political circumstances surrounding a primary.
Cori Bush failed to reclaim her former seat
Former Democratic Rep. Cori Bush also faced another difficult primary in Missouri.
Bush attempted to return to Congress after losing her seat in 2024. She challenged Rep. Wesley Bell in the Democratic primary for the St. Louis-area district.
Bell defeated Bush again.
The contest revived the political rivalry between the two Democrats. Bush remained closely associated with the progressive wing of the party, while Bell entered the race as the sitting representative.
Because the district strongly favors Democrats, the primary carried enormous importance. Bell’s victory put him in a strong position heading into the November election.
Bush’s second defeat also demonstrated the difficulty of reclaiming a congressional seat after losing an incumbent primary.
Ed Case survived a serious Democratic challenge in Hawaii
Not every high-profile primary challenge produced an upset.
Hawaii Rep. Ed Case defeated state Sen. Jarrett Keohokalole in the Democratic primary for the state’s 1st Congressional District.
Case won comfortably, receiving substantially more support than Keohokalole.
The Hawaii contest was significant because it followed several Democratic primary races in which progressive challengers defeated established incumbents.
Case’s victory showed that Democratic voters were not uniformly moving toward challengers from the party’s progressive wing.
His experience and established political organization remained strong enough to withstand the challenge.
The outcome adds balance to the 2026 primary results. While several incumbents have fallen, many others have successfully defended their nominations.
Why these congressional primary upsets matter
The importance of the 2026 results extends beyond individual candidates.
Primary elections determine which candidates will compete for congressional seats in November. When incumbents lose, the general-election campaign begins with a different candidate, a different political message and sometimes a different electoral strategy.
Several factors have contributed to the major primary battles this year.
Redistricting has changed the makeup of congressional districts in states including Texas and Tennessee.
Ideological differences have fueled challenges within both major parties.
National endorsements have played a visible role, particularly in Republican contests.
Grassroots campaigns have helped challengers overcome better-known opponents.
Incumbent fatigue has also created opportunities for candidates promising a change in representation.
The combination has produced an unusually active primary season.
The November contests will tell the larger story
Winning a primary does not guarantee a seat in Congress.
Candidates who succeed in party primaries must now appeal to a broader electorate. That can be particularly important in competitive districts where independent voters and members of the opposing party can determine the outcome.
For candidates in heavily partisan districts, the primary victory may have effectively decided the race. In swing districts, however, the November campaign can look very different from the earlier contest.
The new nominees must also build campaign organizations, raise money and define their positions for general-election voters.
Several of the 2026 primary winners will now face national scrutiny because their races could affect control of the House or Senate.
More primary results are still ahead
The congressional primary calendar has not completely ended.
Several states are holding their contests in August and September, meaning additional incumbent challenges and unexpected victories remain possible.
The next major primary date is August 11, when voters in states including Minnesota and Wisconsin head to the polls. Other states will conduct their primaries later in August and September.
The general election is scheduled for November 3.
Until then, political parties will work to consolidate support around their nominees while campaigns prepare for the final stage of the 2026 election.
The primary results already show that no incumbent can assume another nomination is guaranteed.
What the 2026 results have shown so far
The congressional contests of 2026 have produced major changes on both sides of the political divide.
Republican incumbents have lost to challengers backed by different parts of the party. Democrats have also seen longtime lawmakers defeated by candidates offering new political approaches.
The outcomes in Louisiana, Texas, Kentucky, New York, Michigan, Tennessee, Missouri and Hawaii highlight the variety of forces shaping congressional elections.
Some races were straightforward ideological battles. Others centered on local representation or changed congressional boundaries. In Michigan, an unusual ballot situation produced one of the year’s most surprising Republican nominations.
Taken together, the results have created a November field that looks very different from the one many voters expected at the beginning of the primary season.
The remaining primaries will determine whether more incumbents fall before voters reach the general election.
The 2026 congressional races are entering a decisive stage, and the next round of results could bring even more changes to the November battlefield.