By Andrew Rice
The Center Square

The 2026 midterm elections promise to bring fierce competition as Democrats and Republicans battle for control of Congress.

All 435 seats in the U.S. House of Representatives are up for election in 2026. However, analysts predict only 66 have at least a slight chance of becoming close races.

The U.S. House of Representatives is currently split 220-213 in favor of Republicans, with two vacancies.

The Cook Political Report rates 17 of the 66 races as being true political toss-ups. These include competitions in Arizona, California, Pennsylvania and Washington.

The general Midterm election is Nov. 3, 2026.

Here is a look at some of those competitions before primary elections.

Arizona

The first Congressional district in Arizona is shaping up to be a competitive race in 2026, with incumbent Republican Rep. David Schweikert running for governor.

A crowded field has emerged from those looking to fill Schweikert’s seat. Schweikert narrowly defeated Democrat Amish Shah in 2024 by a margin of about 16,500 votes, just under 4%.

Shah is running for the Congressional seat again, alongside 23 other candidates who expressed interest in running for the seat. An expression of interest is not a formal declaration of candidacy and does not mean a candidate will appear on the ballot for a particular election.

Gina Swoboda, chair of Arizona’s Republican Party, also filed an expression of interest in the congressional race. Swoboda earned an endorsement from President Donald Trump when she entered the race.

“I am deeply honored to have the endorsement of President Trump as we embark on a campaign that will be centered around the common-sense conservative principles of economic growth and prosperity, strong and secure borders, and protecting taxpayers,” Swoboda wrote in a statement.

Arizona faces another competitive race as incumbent Republican Rep. Juan Ciscomani looks to retain his seat in District 6. Nine Democrats have filed statements of interest to challenge Ciscomani for the seat. In 2024, the district went for Trump as president and Democrat Ruben Gallego for U.S. Senate.

Arizona’s primary election is Aug. 4.

California

Following the passage of Proposition 50, several candidates are vulnerable to toss-up races in California. Congressional District 13 was already seen as a swing district before approval of the redistricting measure.

In 2024, Democrat Rep. Adam Gray was elected to Congress by a margin of less than 200 votes, unseating Republican John Duarte.

Kevin Lincoln II, a Republican and former mayor of Stockton, Calif., is also running in District 13 after switching from a run in District 9 due to the passage of Proposition 50. Lincoln has received endorsements from Trump and U.S. House Speaker Mike Johnson.

In the 2024 election, Lincoln lost to incumbent Democrat Josh Harder in California’s 9th Congressional District.

District 22 in California will see incumbent Republican David Valadao trying to retain the seat after the passage of Proposition 50. Democrats Jasmeet Bains, a state assemblywoman, and Randy Villegas, a school board trustee, have announced their candidacy in the area.

“I will fight for my community every day, and work with anyone, to ensure that economic opportunity reaches every part of our community, and that families have access to the essential government programs that keep children fed and healthcare accessible,” Villegas said.

California’s 48th Congressional district will also see incumbent U.S. Rep. David Issa, a Republican, face a slew of Democratic challengers for control of the redrawn district.

Ammar Campa-Najjar, a Democrat who lost to Issa in 2020, is running again.

“Ammar is uniquely positioned to flip this must-win seat from red to blue,” his campaign website reads.

California’s primary election is June 2.

Pennsylvania

Districts 7 and 10 in Pennsylvania are likely to see fierce competition between Democrats and Republicans in 2026.

In 2024, Republican Ryan Mackenzie flipped the seat red. Pennsylvania Gov. Josh Shapiro endorsed firefighter union head Bob Brooks, a Democrat.

“Ryan is keeping his promise to the people of the 7th Congressional District by supporting policies that grow our economy, protect taxpayers, address affordability, address illegal immigration, improve our nation’s safety, and preserve services for those who truly need them,” Mackenzie’s website reads.

District 10 will also see incumbent Republican Rep. Scott Perry defending his seat. Perry first won election to Congress in 2018. Perry narrowly defeated Democrat Janelle Stelson in 2024, retaining the seat.

Stelson is running again for the seat in Pennsylvania’s 10th district.

Pennsylvania’s primary is May 19.

Washington

In Washington’s third congressional district, Republican John Braun is looking to challenge incumbent Democrat Rep. Marie Gluesenkamp Perez.

Perez first won the seat in 2022, after defeating Republican Joe Kent. She again defeated Kent in 2024.

Braun is a fourth-term state senator and Senate minority leader in Washington.

Washington’s primary election is Aug. 4.