The Forecasting MachineOpen interactive report

Will Chris Coons (D) win the Delaware U.S. Senate election on November 3, 2026?

Resolves Yes if Chris Coons (D) is certified as the winner of the Delaware U.S. Senate seat contested on November 3, 2026, and No otherwise. If the contest is not decided on election night — because of a runoff, a ranked-choice tabulation, or a recount — it resolves on the final certified result. Declared candidates: Chris Coons (D); Michael Katz (R).

Forecasted on

Forecast probabilities

  • Yes: 99.1%
  • No: 0.9%

Reasoning

Coons is overwhelmingly favored, with a 99.1% chance of winning and a 0.9% chance of losing. Delaware’s strong Democratic lean, Coons’s incumbency and financial advantage, and a late-October national environment favorable to Democrats all point in the same direction; the remaining uncertainty is mostly about rare, unforeseen events.

Yes — 99.1%: The fundamentals strongly favor Coons

Delaware is the anchor of this forecast. Kamala Harris carried the state by about 15 points in 2024, Democrats hold its other federal and statewide offices, and the Senate seat has been in Democratic hands since 2001 [a5, a9, a10]. Coons is a familiar incumbent seeking another term, and he won nearly 80% of the Democratic primary vote [e1, e106]. The primary result is not a measure of the general-election margin, but it does offer little sign of a serious intraparty threat.

The candidates also enter the general election with sharply different resources. Coons has raised about $6.9 million, compared with roughly $159,000 for Katz, and forecasters rate the race Solid Democratic [a3, a4, a7]. Katz won his Republican primary decisively, but that shows strength among Republican voters, not statewide reach [e59]. His prior run as an independent in 2024 brought only 4% of the vote [a2, a9, a10]. His effort to build a cross-party coalition and his medical and business background add some potential appeal, but do not by themselves overcome Delaware’s partisan baseline. Republican friction—including backlash after Katz criticized the House nominee over misgendering Sarah McBride, and a primary rival’s write-in bid—may further complicate party unity [a6, a9].

The broader political climate offers no obvious counterweight. Late-October national polls generally show Democrats ahead on the generic congressional ballot: the RealClearPolling average was about D+8, while individual surveys reported leads ranging from four points to double digits [e109, e111, e112, e114, e116, e117]. Several forecasters also moved races toward Democrats [e107, e115]. These national numbers do not predict Delaware’s Senate result directly, and a national Senate outlook can still favor Republicans because competitive states determine control of the chamber [a8, e108]. But they provide no basis for expecting a Republican upset in a state as Democratic as Delaware.

Coons and Katz held public forums and debates on health care, immigration, foreign policy, tariffs, spending, and other issues. The campaign activity reported so far offers no sign of a major disruption or a matchup-specific poll showing the race to be unexpectedly close [e55, e56, e57, e80, e88, e89]. Early voting is under way, further narrowing the time for a late campaign development to change the outcome [e110].

No — 0.9%: A small residual risk remains

There is no cited Coons–Katz general-election poll, so the forecast cannot rely on a direct measurement of the candidates’ standing. Katz is a credible Republican nominee who won his primary, and an unusual turnout pattern or a major late-breaking event could still alter a race. More remote possibilities—including a health emergency or a problem with certification—also remain relevant to a question resolved by the final certified result.

Why the probabilities are so lopsided

The evidence is not perfectly complete: the absence of a matchup poll leaves more uncertainty than a direct measure would. But that gap is outweighed by the convergence of Delaware’s partisan history, Coons’s incumbency and fundraising advantage, Katz’s limited record of statewide support, and a national environment that is not tilting against Democrats. The 99.1% probability for Yes reflects that unusually strong alignment; the 0.9% for No preserves room for the small risks that fundamentals cannot rule out.

Update summary

New national polls and election ratings continue to point toward a favorable environment for Democrats, including a revised Senate outlook, but these updates provide no direct evidence of a change in Delaware’s race [e107, e108, e109, e112, e114]. No matchup-specific poll or significant campaign development emerged.

Cited evidence