Cook Lists Seven Senate Toss Ups as Forecast Models Split on Chamber Control

Cook's seven seat Toss Up board

Cook Political Report's September 15 Senate ratings list seven Toss Up races among the 35 seats on the 2026 ballot: Alaska, Iowa, Maine, Michigan, New Hampshire, Ohio, and Texas (Cook Political Report, September 15, 2026; Newsweek, September 18, 2026). Georgia and North Carolina sit at Lean Democrat on the same Cook table. The biggest recent change was New Hampshire, moved from Lean Democrat to Toss Up on September 15 as former Republican Senator John E. Sununu challenges Democratic Representative Chris Pappas for the open seat Jeanne Shaheen is leaving (Washington Examiner, September 15, 2026; Newsweek, September 18, 2026).

Cook's summary columns after that update show Solid Democrat 9, Likely Democrat 1, Lean Democrat 2, Toss Up 7, Lean Republican 0, Likely Republican 2, and Solid Republican 14 among seats up this cycle (Cook Political Report, September 15, 2026). Republicans defend a 53 to 47 majority. Democrats need a net of four Republican held seats without losing their own because Vice President JD Vance would break a 50 to 50 tie (Newsweek, September 18, 2026).

What sits inside each Toss Up

Iowa moved from Lean Republican to Toss Up in August as Representative Ashley Hinson defends retiring Senator Joni Ernst's seat against state Representative Josh Turek in a state President Donald Trump carried by about 13 points in 2024 (Newsweek, September 18, 2026). Texas also moved from Lean Republican to Toss Up in August after Attorney General Ken Paxton defeated Senator John Cornyn in the Republican runoff and drew Democratic state Representative James Talarico (Newsweek, September 18, 2026).

Ohio pits appointed Republican Senator Jon Husted against former Democratic Senator Sherrod Brown. Alaska pairs Republican Senator Dan Sullivan with former Democratic Representative Mary Peltola under ranked choice rules. Maine has Republican Senator Susan Collins seeking a sixth term against Democrat Troy Jackson. Michigan matches Democrat Abdul El-Sayed against Republican Mike Rogers for the open seat (Newsweek, September 18, 2026). Those seven names are the competitive spine. They are not interchangeable.

Where the models diverge from the qualitative boards

Sabato's Crystal Ball rates five Senate races as Toss Ups, one fewer than Cook, after moving Texas from Lean Republican in late August (Newsweek, September 18, 2026). Managing editor Kyle Kondik wrote that Republicans probably retain a slight edge, while noting that assessment is harder to defend than at any point this cycle. His individual best guesses on the five Toss Ups add to a 50 to 50 Senate decided by Vance's tie break (Newsweek, September 18, 2026).

Probability models print a different temperature. FiftyPlusOne gave Democrats a 65 percent chance of Senate control as of midweek, with a median simulated outcome of 51 to 49 Democratic (Newsweek, September 18, 2026). Decision Desk HQ put Democrats at 51 percent and Republicans at 49 percent, also with a 51 to 49 Democratic median after having Republicans favored 60 to 40 as late as July 24 (Newsweek, September 18, 2026). Nate Silver's FLIPR model put Democratic Senate chances at 59 percent as of September 15, citing Times/Siena near Democrats plus 8 and Economist/YouGov likely voters near Democrats plus 12 (Newsweek, September 18, 2026). Qualitative Toss Up counts and simulated probabilities are related instruments. They are not the same receipt.

How the deep red defense story lands on the same board

The New York Times reported September 17 that Republicans are mounting a costly defense in states and districts Trump carried easily in 2024, including private GOP discussion about whether Georgia has drifted beyond reach, Vice President Vance campaigning in Kansas, a new Republican super PAC for Nebraska's incumbent, and Trump aligned money flowing into deep red Senate and House fights, including Texas districts drawn a year ago (New York Times, September 17, 2026). AdImpact tracking cited by the Washington Post found Republicans set to spend nearly $140 million more than Democrats on ads in the nine most competitive races in the final weeks, including about $39.6 million reserved in Texas against $5.1 million for Democrats (Washington Post via The Philadelphia Inquirer, September 18, 2026).

US Political Rank keeps those races on 2026 Senate races and district pressure on most competitive House districts of 2026. A Lean Democrat rating in Georgia is not a finished seat. A $39.6 million Texas ad reserve is not a finished canvass. Name the rater. Name the reservation. Leave November 3 to finish the arithmetic.

What the forecast split settles and what it leaves open

Settled on this week's Senate desk: Cook's seven Toss Ups after the New Hampshire move; Crystal Ball at five Toss Ups with a slight Republican edge call; FiftyPlusOne near 65 percent Democratic; Decision Desk HQ near 51 percent Democratic; FLIPR near 59 percent Democratic; Democrats still needing a net of four under 53 to 47 math (Cook Political Report, September 15, 2026; Newsweek, September 18, 2026). Settled on the money desk: a large Republican ad reservation advantage in the top competitive races, especially Texas (Washington Post via The Philadelphia Inquirer, September 18, 2026).

Still open: whether New Hampshire stays a true Toss Up through October, whether Iowa and Ohio polls are overstating Democrats as Kondik warns, whether Texas money closes the Paxton Talarico gap, and whether any model median survives contact with ranked choice Alaska and the full early vote. Forty six days remain. A country that can publish seven named Toss Ups, five rival models, and nine race ad reservations in the same week is measuring itself in public. Score every instrument. Wait for the only grid that ends the argument: the certified Senate.