Five Weeks Out: The Seven Senate Toss-Ups That Will Decide Control
Cook Political Report now rates seven Senate seats as coin flips: five held by Republicans, two by Democrats. Democrats need to net four seats. Here is every race on the board, the September polling, and the arithmetic.
In mid-August the Senate fight ran through four Toss-Ups. It now runs through seven. Since August 19, Cook Political Report has moved Texas and Iowa from Lean R to Toss-Up (Aug. 20), New Hampshire from Lean D to Toss-Up (Sept. 15), Georgia from Lean D to Likely D, and Kansas and South Carolina one step toward Democrats (Sept. 23). The markets moved too. On September 29, Kalshi and Polymarket priced Democratic control of the Senate at about 63%. Decision Desk HQ’s forecast, updated September 28, is more cautious at 54%.
The arithmetic
Republicans hold 53 seats. Democrats hold 45, plus two independents who caucus with them. Vice President JD Vance breaks ties, so Democrats need 51 — a net gain of four. Thirty-five seats are on the ballot: 22 held by Republicans (including special elections in Ohio and Florida) and 13 by Democrats.
The seven Toss-Ups split five Republican-held seats (Maine, Ohio, Texas, Alaska, Iowa) and two open Democratic seats (Michigan, New Hampshire). North Carolina, rated Lean D, is the only Republican-held seat already leaning Democratic. The simplest Democratic majority therefore looks like this: hold Michigan and New Hampshire, win North Carolina, and take three of the five Republican-held Toss-Ups. Every Democratic seat lost adds one more Republican seat they would have to take.
The five Republican-held Toss-Ups
Maine · Sen. Susan Collins (R) vs. Troy Jackson (D)
Three September polls produced two different leaders. Jackson, a logger from Allagash and former state Senate president, became the nominee at a July 25 convention after Graham Platner withdrew. Maine Public has described him as “swamped by GOP ads.” Collins is the only Republican senator on the ballot in a state Kamala Harris carried in 2024, by about seven points. Four televised debates are scheduled: Oct. 6, 8, 13 and 15.
Ohio · Sen. Jon Husted (R) vs. Sherrod Brown (D) · special election
The most expensive Senate race of the year: AdImpact counted $72.1 million in ads and reservations by September 11. Former Sen. Sherrod Brown is trying to win back a Senate seat two years after losing his own by about 3.6 points, in a state Trump carried by 11. Marist’s poll released September 29 had Brown up eight among registered voters; Quantus had it tied among likely voters. Ohio’s registration deadline is Oct. 5, and early voting starts the next day.
Texas · Ken Paxton (R) vs. James Talarico (D)
The race that most changed the map. Paxton ousted Sen. John Cornyn 63.8%–36.2% in the May runoff, and Talarico has led both of the latest public polls. No debate has been agreed. Talarico accepted three proposed dates that Paxton never confirmed, Fox News has offered to host one, and CNN has scheduled a Talarico town hall for Oct. 14 with Paxton invited. The structural hill is real: Trump carried Texas by about 14 points in 2024, Texas has not elected a Democrat statewide since 1994, and its last Democratic senator won in 1988. Registration closes Oct. 5; early voting runs Oct. 19–30.
Alaska · Sen. Dan Sullivan (R) vs. Mary Peltola (D) · ranked choice
Peltola took 49.5% to Sullivan’s 41.4% in the August top-four primary. November’s ranked-choice ballot adds two more Republicans: Petersburg’s Daniel J. Sullivan and Gerald Heikes, who moved up when Democrat David Leslie withdrew at the Aug. 31 deadline. AARP’s September poll had Peltola ahead by five in the first round and 53–47 after ranked-choice tabulation. Trafalgar had Sullivan up one. We walk through how the rounds could play out in Alaska’s ranked-choice math.
Iowa · Rep. Ashley Hinson (R) vs. Josh Turek (D) · open
Sen. Joni Ernst is retiring. Turek, a Paralympic gold medalist and state representative, leads both recent polls, though InsiderAdvantage has it within a point. Tariffs and farm prices have been central issues, and the top of the ticket is moving the same direction: Democrat Rob Sand led the governor’s race 54–42 in the same Marist survey. Debates are set for Oct. 7 on Iowa PBS and Oct. 13 on Nexstar/WHO.
The two Democratic-held Toss-Ups
Michigan · Abdul El-Sayed (D) vs. Mike Rogers (R) · open
Sen. Gary Peters is retiring. El-Sayed, who upset Rep. Haley Stevens in the August primary despite being outspent roughly eight to one, has led both September polls by five points. Rogers, a former House Intelligence Committee chairman, lost Michigan’s 2024 Senate race by about 0.3 points. The governor’s race above them is now a two-way contest, and Democrat Jocelyn Benson leads it. The Senate candidates debate Oct. 8 in Grand Rapids and Oct. 21 on WXYZ.
New Hampshire · Chris Pappas (D) vs. John E. Sununu (R) · open
Sen. Jeanne Shaheen is retiring. Sununu, who held this seat from 2003 until Shaheen beat him in 2008, easily won the Sept. 8 Republican primary over former Massachusetts Sen. Scott Brown, and two raters moved the race to Toss-Up. The first post-primary polls, though, both show Pappas ahead by six to eight points.
Leaning, and pulling away
North Carolina · Roy Cooper (D) vs. Michael Whatley (R) · open
Sen. Thom Tillis is retiring. Former Gov. Roy Cooper led AARP’s poll 53–42 and Opinion Diagnostics’ 52–44. Trump rallied for Whatley, the former RNC chair, in Gastonia on Sept. 16. As of Sept. 10 the campaigns had not agreed to any debates. North Carolina’s registration deadline is Oct. 9, and same-day registration is available during early voting.
Georgia · Sen. Jon Ossoff (D) vs. Mike Collins (R)
Ossoff led InsiderAdvantage 50–42 and YouGov 52–42. Gov. Brian Kemp endorsed Rep. Mike Collins on Sept. 14, and the two debate Oct. 8. Georgia is the one battleground where Democrats are outspending Republicans on Senate ads, according to AdImpact.
That summary needs a caveat. Most of these leads are within the margin of error, several polls are of registered rather than likely voters, and Republicans are outspending Democrats in nearly every battleground Senate race. The second tier is also moving, and not all of it in one direction. Kansas and South Carolina have tightened, but so has Minnesota, a Democratic-held open seat where one September poll was tied.
What to watch in October
- Oct. 5: voter registration closes in Texas, Georgia, Ohio, Arizona and Florida.
- Oct. 6, 8, 13, 15: Collins and Jackson debate in Maine.
- Oct. 7 and 13: Hinson and Turek debate in Iowa.
- Oct. 8: Senate debates in Michigan and Georgia.
- Oct. 14: CNN’s Texas town hall, and the September inflation report.
- Oct. 19: Texas early voting opens.
- Oct. 21: second Michigan Senate debate.
Every rating, poll and date on this page is tracked live on the Election Tracker Senate map.
Sources
- Cook Political Report: Senate race ratings
- Axios: Cook shifts Georgia, Kansas and South Carolina (Sept. 23)
- Washington Examiner: Cook moves New Hampshire to Toss-Up (Sept. 15)
- Marist Poll: Texas, September 2026
- Spectrum News: UNH Maine poll (Sept. 25)
- Newsweek: AARP Alaska poll (Sept. 17)
- Axios: Senate ad spending (Sept. 11)
- Decision Desk HQ 2026 forecast