With table set for Senate battle, here are the races to watch

New Hampshire’s primary contests on Tuesday finished off the primary season and cemented the remaining candidates for the key Senate races that will decide whether Democrats or Republicans control the upper chamber following the November contests.

In total, 33 of the chamber's 100 senators are seeking reelection with at least a half-dozen of their races considered toss-ups – meaning the outcome could go either way. 

RealClearPolitics' polling average ranks Maine, New Hampshire, Ohio, Michigan, Iowa, Texas and Alaska as toss-ups. Of those seven, five are held by Republicans and two are Democrat held. 

With the Senate makeup now 53 Republicans and 47 Democrats, including Vermont Independent Sen. Bernie Sanders, Democrats will have to win a net total of four seats to retake control of the chamber. 

“You can’t get any tighter than what we’re looking at right now. Democrats with a 50% chance to win the Senate. Republicans with a 50% to hold the Senate,” CNN polling and data journalist Harry Enten said this week. “It is even at this point, eight weeks until Election Day.”

Enten also broke down an aggregation of poll-based models, which gave the Democrats a 53% chance to win the upper chamber, and betting odds, which gave them a 47% chance to win.

Republicans need only win three of the toss-up races to keep control of the Senate, given the Trump administration’s control of the White House gives Vice President JD Vance the tie-breaking vote.

But whereas the Senate was previously thought to be a lock for the Republicans, unexpected developments in several races have made several contests more competitive than usual. Here’s a look at those races.

Alaska

GOP Sen. Dan Sullivan is facing a close reelection against former Democratic Rep. Mary Peltola, who has previously managed to win statewide in the typically red state. Peltola won a special election in 2022, before securing a full-term in the November contest. She lost reelection in 2024.

Complicating the race is the presence of a Republican candidate who shares the name, Dan Sullivan, on the ballot. Republicans have accused him of a bad-faith attempt to confuse voters, though he has survived challenges to his eligibility.

The off-brand Sullivan’s presence and Alaska’s ranked choice voting system are expected to benefit Peltola, who currently leads the race by an average 2.0%.

Maine

Incumbent GOP Sen. Susan Collins faces her first reelection bid since the 2022 Dobbs v. Jackson decision that overturned the constitutional right to an abortion. 

While Collins has carved out a lane as a pro-choice Republican, she voted to confirm Associate Justice Brett Kavanaugh, who went on to vote to overturn Roe v. Wade. The 2026 contest will be her first time on the ballot since that development – in a state known to elect moderate candidates but leans slightly Democrat.

The 73-year-old Collins was initially set to face Democratic nominee Graham Platner, who ran as a progressive outsider candidate. But Platner dropped out after a series of scandals and was replaced by former state Senate President Troy Jackson.

Jackson leads by an average 2.3%, but Collins has a long history of outperforming the polls. In 2020, she won by 8.6% against then-state Democratic House Speaker Sara Gideon, despite most polls showing Gideon with a high single-digit lead.

New Hampshire

The state hasn’t sent a Republican to the Senate since Kelly Ayotte, who is now the governor. She won a single term in 2010. In addition, the state hasn’t backed a Republican at the presidential level since 2000.

Republicans are hoping to break the streak with nominee John Sununu, who represented the state in the Senate from 2003 to 2009 and the brother of former Gov. Chris Sununu. He will face Democratic nominee Rep. Chris Pappas, who after winning the party nomination Tuesday night leads Sununu by an RCP average 2%.

They are competing for the seat of Democrat Sen. Jeanne Shaheen who is not seeking reelection.

Ohio

GOP Sen. Jon Husted is facing a close match against former Democrat Sen. Sherrod Brown, who is hoping to reclaim a spot in the state’s delegation after losing his own to GOP Sen. Bernie Moreno in 2024.

Husted was appointed to fill the seat vacated by Vice President JD Vance in early 2025. He previously served as the state’s lieutenant governor and has won a statewide election before. But the same can be said of Brown, who served three terms in the Senate.

While Ohio has moved from a swing state toward leaned Republicans in recent years, Husted may suffer from his status as an appointed office holder, who tend to underperform when placed on the ballot. Brown leads by an average 2.6%.

Michigan

The state poses the most likely opportunity for Senate Republicans to gain a seat this cycle. With Democrat Sen. Gary Peters  not seeking reelection, the November race has been boiled down to former GOP Rep. Mike Rogers and Democratic candidate Abdul El-Sayed, a progressive. 

Rogers previously lost a close 2024 Senate contest to now-Democrat Sen. Elissa Slotkin and did not face a serious primary challenge this cycle. 

El-Sayed narrowly defeated Democratic Rep. Haley Stevens for the party nomination. Though polls had indicated a landslide for him, he substantially underperformed those projections and only narrowly clinched the party nomination.

Rogers has attempted to paint El-Sayed as a radical, pointing to his support from far-left organizations and his association with streamer Hasan Piker. 

El-Sayed has distanced himself from some groups, like the Democratic Socialists of America, rejected the “socialist” label outright, and attempted to present himself as a progressive, albeit one within the normal range for a Democratic candidate.

El-Sayed currently leads by an average 1.7% against Rogers.

Iowa

Like Ohio, Iowa has drifted toward the Republicans in recent cycles. The contest is noticeably the only toss-up in which the Republican candidate has an outright lead, albeit slim. GOP Rep. Ashley Hinson leads Democratic nominee Josh Turek, a state representative, by an average 1.8%.

The lead is substantially less than the double-digit margin President Donald Trump had in winning Iowa in 2024 but also lower than most polls overall. A Fox News poll from June showing Turek with a 4-point lead appears to be an outlier bringing down the average.

The seat is open because GOP Sen. Joni Ernst is not seeking reelection. Polymarket odds currently give Hinson a 66% chance of succeeding her.

Texas

The Lone Star State broke for Trump by roughly 14 points in 2024, erasing decades of slow Democratic gains in the Republican stronghold. But the 2026 Senate contest is a toss-up, and Democratic nominee state Rep. James Talarico currently holds a 2.4% average lead over Republican state Attorney General Ken Paxton.

Paxton has previously won multiple statewide races and even survived an impeachment attempt from members of his own party. But his longstanding beef with the establishment wing of the party appears poised to come back to haunt him.

The conservative firebrand beat out GOP Sen. John Cornyn in the party primary this year. While Cornyn placed first in the first round, he ultimately lost to Paxton in the runoff. Paxton had offered to drop out of the race altogether if Cornyn could secure passage of the SAVE America Act, a marquis voter ID bill, though Cornyn could not do so. Trump cited the SAVE America Act issue when endorsing Paxton for the runoff.

Ben Whedon is the Chief Political Correspondent for Just the News. Follow him on X.