Delaware's Final Primary Before the Midterms: What to Know

Delaware votes on Tuesday, September 15, 2026, in the last state primary before the November 3 midterm general election. Polls open at 7am ET (12:00 GMT) and close at 8pm ET (00:00 GMT). Al Jazeera

Delaware uses a closed primary. Think of it as a members-only vote. Only registered Democrats can vote in the Democratic primary, and only registered Republicans can vote in the Republican primary. A party holds a primary for an office only if more than one candidate from that party is running. A candidate with no opponent in the primary moves directly to the general election.

The voter pool is small and leans Democratic by registration. As of September 1, 2026, Delaware had about 808,000 registered voters, including about 331,000 registered Democrats and about 199,000 registered Republicans. Al Jazeera The Delaware Department of Elections provides separate Election Day polling place listings for Kent County, New Castle County and Sussex County for the September 15 primary. Delaware Department of Elections

The most closely watched contest is for the U.S. Senate. Democratic U.S. Senator Chris Coons is seeking re-election and faces three primary opponents in his bid for a third full term. The challengers are Jeff Appelhans, Mary Louve and Eric Hansen. The official sample ballot for the Democratic primary lists the Senate contest as "Vote for 1" with Jeff Appelhans, Chris Coons, E. No-Trump Hansen and Mary Louve as the choices. Delaware Department of Elections Hansen was the Republican U.S. Senate nominee in Delaware in 2024 and is now running as a Democrat under the ballot name "E. No-Trump Hansen." Al Jazeera

On the Republican side, former state Senator Michael Katz and U.S. Army Reserve Colonel John Shulli are competing for the Republican nomination for U.S. Senate. The winners of the Democratic and Republican primaries will meet in November.

Delaware's U.S. House race follows a different pattern. The 2026 primary includes races for the U.S. Senate and U.S. House. NPR Sarah McBride is Delaware's sole representative in the U.S. House and the first out transgender member of the U.S. Congress. She is unopposed in her primary as she seeks a second term and will advance to November without a primary contest. Three Republicans, Joseph Arminio, Earl Cooper and John Whalen, are competing to face McBride in November for the House seat.

Down-ballot offices are also on the primary calendar. Delaware's Democratic state attorney general is seeking re-election, alongside Coons and McBride. Voters will also choose nominees for the state legislature and for an open state treasurer seat. The state's candidates calendar places the September 15 statewide primary alongside earlier 2026 contests including May 12 school board elections. Delaware Department of Elections

The broader context here is a state where Republicans face steep structural odds in federal and statewide races. Republicans have not won the Delaware governorship since 1988. They have not won a U.S. Senate seat in Delaware since 1994. They have not won Delaware's U.S. House seat since 2008. Al Jazeera

In my view, that history helps explain why the process details matter more than usual for people watching this primary closely. A late, closed primary with a compressed seven-week run to November 3 rewards organization over persuasion. Turnout will come from registered partisans, not independents. Contested nominations must consolidate quickly. Unopposed incumbents can conserve resources while challengers spend through September. For a small electorate divided among three counties, county-level margins and legislative primaries may offer the clearest read on party infrastructure heading into the midterms.