Senate math: 35 seats up, 13 in play, and what Democrats need

Voters across the United States are casting ballots on Tuesday, November 3, 2026, to decide which party will control Congress for the final two years of President Donald Trump's second term. The Senate race is a central focus of this midterm election, with 35 of the 100 seats up for grabs. According to Ballotpedia, this total includes 33 regular elections and two special elections for the remaining terms of Marco Rubio in Florida and JD Vance in Ohio. Republicans currently hold 53 seats, while Democrats hold 45, plus two independents who caucus with the Democratic party. The outcome will determine whether Democrats gain enough power to conduct oversight of the administration or if Republicans maintain their narrow majority.

Democrats need a net gain of four seats to secure a majority in the Senate, according to Ballotpedia. This means they must win more seats than they lose by that specific margin. Republicans can afford to lose only two seats and still retain control. Eleven senators, four Democrats and seven Republicans, are not running for re-election, creating open seats that add complexity to the race. Winners in these contests will begin their six-year terms on January 3, 2027. The math is tight, with the Associated Press noting that one or two seats could tip the balance of power in either chamber.

Thirteen Senate races are considered battlegrounds, as identified by Ballotpedia. These include contests in Alaska, Florida, Georgia, Iowa, Kansas, Maine, Michigan, Montana, Nebraska, New Hampshire, North Carolina, Ohio, and Texas. The 2024 presidential margin in each state provides context for the current race. For example, Alaska and Florida are special or incumbent races where Donald Trump won by more than 13 points. Georgia is a Democratic-held seat where Trump won by 2.2 points. Iowa is an open seat where Trump won by 13.2 points. Kansas is a Republican-held seat with a Trump margin of 16.2 points.

Maine stands out as a key competitive race because it is the only battleground where Kamala Harris won in 2024, with a margin of 6.9 points. Susan Collins, the Republican incumbent, is facing a challenge from Democratic former state Senate President Troy Jackson. The Associated Press notes that economic strain and tariffs have made the state competitive. In New Hampshire, another Harris-won state with a 2.8 point margin, Democratic Representative Chris Pappas is running against former Republican Senator John E. Sununu for the seat left by retiring Democrat Jeanne Shaheen. Michigan is also a battleground with a narrow 1.4 point Trump margin, featuring a race between Republican former Representative Mike Rogers and Democrat Abdul El-Sayed.

Race ratings as of October 27 provide a snapshot of the current landscape according to Cook, Decision Desk, Inside Elections, and Sabato. Maine is rated a toss-up by all four organizations. Iowa is considered a toss-up or a lean Republican race. Kansas is viewed as a toss-up to lean Republican. Alaska and Michigan are both rated toss-up to lean Democratic. Georgia is seen as a lean to likely Democratic race. These ratings suggest that while Democrats have a path to victory, they must perform well in states that lean Republican, particularly in the Midwest and Mountain West.

Republicans have a significant financial advantage in this election cycle, which may be the most expensive in history. According to an Associated Press analysis of AdImpact data, Republican committees have outraised and outspent their Democratic counterparts, aided by Trump-affiliated groups and Elon Musk. At the candidate level, however, Democrats have outraised their opponents. A striking 88.1% of Republican general election television advertising spending went to states and districts that Donald Trump won in 2024. This includes more than $850 million in states where he won by 10 points or more, indicating a heavy focus on protecting Republican-held seats in solidly red areas.

Redistricting has also shaped the political landscape, with six states using new congressional maps for this mid-decade election: California, Florida, Missouri, North Carolina, Tennessee, and Texas. Ohio is also using a new map. These changes may affect the competitiveness of certain districts and seats. Republicans attempted to use redistricting to beat the traditional midterm pattern where a president's party usually loses seats. However, the Associated Press notes that new districts in Florida and other states may not vote as they were drawn, adding uncertainty to the final outcome.

The mood among voters reflects a referendum on the current administration, with many citing high prices and an unpopular war with Iran as key concerns. Associated Press and NORC polling shows that 35% of U.S. adults approve of Trump's job performance, while only 25% approve of his handling of the economy. About 7 in 10 Americans say the country is heading in the wrong direction, with most blaming the president for high prices. Democrats are described as cautiously optimistic, while Republicans are bracing for the possibility of losing the House and fighting to hold the Senate.

More than 57 million people had already voted by Monday, surpassing early vote totals from four years ago in many closely watched states. The U.S. Postal Service has added hours, staff, and special lines to ensure mail ballots are counted on time. A federal judge temporarily barred the Trump administration from carrying out a plan to prevent noncitizen voting, a move critics say risks disenfranchising eligible voters. Another judge ordered the administration to stop demanding that California election officials segregate ballots cast by people on lists of suspected noncitizens. These administrative actions are part of a broader effort to ensure the integrity of the vote as polling places open.