Delaware voters cast their ballots Tuesday in the final primary of the 2026 election cycle, concluding a season that saw significant victories for progressive and socialist candidates over establishment rivals and highlighted Donald Trump's enduring influence in Republican races.
Incumbent Democratic Sen. Chris Coons and state Attorney General Kathy Jennings faced primary challengers, while Democratic Rep. Sarah McBride ran unopposed. These contests serve as tune-ups for the general election, where Republicans aim to challenge the Democratic Party's hold on statewide offices in Delaware.
This primary season has been notable for shifts within the Democratic Party, with several candidates backed by progressive or Democratic Socialists of America (DSA) groups achieving victories, sometimes unseating long-term incumbents. This trend follows earlier successes, such as New York City Mayor Zohran Mamdani's 2025 primary win. In June, DSA-backed contenders like Melat Kiros defeated 15-term incumbent Democratic Rep. Diana DeGette in Colorado, and Darializa Avila Chevalier unseated five-term Democratic Rep. Adriano Espaillat in New York.
August saw further key wins for the left in statewide Senate primaries, with Abdul El-Sayed winning in Michigan, Lt. Gov. Peggy Flanagan in Minnesota, and state Rep. Angie Nixon in Florida. While not every progressive candidate succeeded, such as Francesca Hong's defeat in Wisconsin's gubernatorial primary, the left has demonstrably increased its influence within the party. Many successful progressive candidates campaigned on platforms advocating for the abolition of ICE, reductions in military aid to Israel, and the implementation of a single-payer healthcare system.
"It is undeniable that progressives have built a coalition and have a message that can serve to buoy a candidate when they are an acceptable alternative to the status quo," said Joe Caiazzo, a Democratic strategist who worked on Sen. Bernie Sanders' presidential campaigns. He added that for progressives to maintain success, they must "put forward candidates who are serious, credible, and are accessible to the public."
On the Republican side, Donald Trump has asserted the strength of his endorsements. According to a Fox News tracker, Trump's endorsed candidates had a perfect record in GOP Senate primaries and a near-perfect record in House Republican primaries this cycle. Trump has significantly reshaped the Republican Party since 2016, with the MAGA and America First movements gaining prominence.
However, Trump's influence is not absolute. Five of his endorsed gubernatorial candidates lost their Republican primaries this year, including Georgia Lt. Gov. Burt Jones and South Carolina Lt. Gov. Pamela Evette. "The Republican Party is Trump’s party, and there’s no question that an endorsement from the president provides a tremendous boost in a Republican primary. But it doesn’t necessarily mean the candidate’s going to win," commented veteran GOP strategist Ryan Williams. He noted that while Trump maintains a firm grip on the party, "if there are underlying issues with a candidacy, those can pose problems that even an endorsement can’t overcome."
In Delaware's primary contests, Sen. Chris Coons is seeking a third full term and faced challenges from Jeff Appelhans, Mary Louve, and Eric Hansen. The Republican nomination for the Senate seat is contested by former state Sen. Michael Katz and U.S. Army Reserves Col. John Shulli.
Rep. Sarah McBride is unopposed in the Democratic primary for her House seat. Republicans Joseph Arminio, Earl Cooper, and John Whalen are competing for their party's nomination.
State Attorney General Kathy Jennings is being challenged in the Democratic primary by attorney Dwayne Bensing and domestic violence victims advocate Patty Rickman. David Graham is unopposed for the Republican nomination for Attorney General.