Senate
Dark: on the ballotLight: not up in 2026
Republicans control both chambers. On Nov 3, all 435 House seats and 35 of the 100 Senate seats are on the ballot. Democrats need a net gain of 4 seats in the Senate and 4 in the House to take control.
Dark: on the ballotLight: not up in 2026
2 vacant1 independent
Seat counts checked Nov 1, 2026 against the Clerk of the U.S. House and the U.S. Senate. Net gains count from today's seats. Toss-ups: Hume Outlook as of Oct 28, 2026.
18 races where the Hume Outlook leader is at 60% or less, closest first · as of 2026-10-28.
Cook moved Alaska from Lean R to Toss Up on July 1, 2026 (Cook race page).
One of two Democratic-held seats up in a state Trump won in 2024 (by 2.2 points), and Republicans' best pickup target; Cook nonetheless moved it from Toss Up to Lean D on April 13, 2026 (Cook race page; Fox News, April 13, 2026).
Cook moved Iowa from Lean Republican to Toss Up on Aug 20, 2026, writing that Rep. Ashley Hinson is one of the GOP's best recruits but that the political environment is 'uniquely challenging' for Republicans there (Cook race page; Spectrum News, Aug 20, 2026).
Collins is the only Republican senator up in a state Harris carried, and Cook has rated the race Toss Up since Oct 14, 2025 (Cook race page).
The only open Democratic-held seat in a state Trump won in 2024 (by 1.4 points), rated Toss Up by Cook since its first 2026 ratings on Feb 11, 2025 (Cook race page; Wikipedia).
Included as the cycle's three-way race; Cook still rates it Solid R (race page 'last updated Feb 11, 2025'); Inside Elections moved it from Solid R to Likely R on March 10, 2026 (Roll Call) and rates it Solid R as of Sept 3, 2026 (Wikipedia ratings table, read Sept 13, 2026).
Rated Lean D since Cook's first 2026 ratings on Feb 11, 2025, but Cook's summary says Republicans are 'bullish' after polling showed a statistical tie between Rep. Chris Pappas and former Sen. John E. Sununu (Cook race page).
Cook calls this 'the GOP seat Democrats are most likely to flip' and moved it from Toss Up to Lean D on April 13, 2026 (Cook race page; Fox News, April 13, 2026) - the only Republican-held seat Cook rates in the Democratic column.
Cook moved this special election from Lean Republican to Toss Up on April 13, 2026, citing former Sen. Sherrod Brown's $12.5 million first-quarter haul and polls showing a dead heat (Cook race page; Fox News, April 13, 2026).
Cook moved Texas from Lean Republican to Toss Up on Aug 20, 2026 (Cook race page, 'last updated Aug 20, 2026'; Washington Post and Spectrum News, Aug 20, 2026), a state Trump carried by double digits in 2024.
Ratings are third-party editorial calls, cited with their last-updated date; a race without one shows none. Money on each race page is the FEC candidate-level summary through the coverage date it names; polling, seat lean and the prior result carry their own as-of dates. Where district-level data is incomplete, estimates rest on available inputs. Hume model estimate · built on polls, fundamentals, and markets
Sources: FEC filings · Polls: FiveThirtyEight / VoteHub (CC BY 4.0) · Prior results: MIT Election Data + Science Lab (CC0) · Ratings: Cook Political Report · Hume PVI and Hume Outlook: Hidden Levers estimates.
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