A series of retirements, candidate shakeups and high-stakes legislation has redefined the battlefield for control of the Senate in 2026, as both parties brace for competitive showdowns in five states that could determine the majority, The Hill reported.

The 2026 Senate map is beginning to take shape, with five battleground states emerging as the most likely to flip as President Donald Trump and congressional Republicans push major legislative wins and Democrats hunt for openings to reclaim ground.

The top spot now belongs to North Carolina, where Sen. Thom Tillis, R-N.C., stunned colleagues with his announcement that he will not seek a third term. The move has created a power vacuum in a state both parties were already targeting. The Cook Political Report responded by shifting its race rating from "lean Republican" to "toss up."

Former Gov. Roy Cooper (D), a proven statewide vote-getter, is weighing a run, prompting excitement among Democrats. Cooper has never lost a statewide contest in six tries. On the GOP side, all eyes are on Lara Trump, a North Carolina native and wife of Eric Trump. “Lara Trump’s very viable,” said Sen. Ted Budd, R-N.C., “She’s from Wilmington, she went to the same high school as Michael Jordan.”

Republicans are facing recruitment woes in Georgia, where Sen. Jon Ossoff, D-Ga., is up for reelection. The GOP suffered a major blow when Gov. Brian Kemp (R) opted against running. Rep. Buddy Carter, R-Ga., is already in the race, but others like Rep. Mike Collins, R-Ga., and Veterans Affairs Secretary Doug Collins remain under consideration.

“Georgia’s going to be really tough,” one GOP operative said. “Ossoff is not the best candidate, but ... he’s figured out the way to make it work.” Ossoff is bolstered by strong fundraising, bringing in more than $10 million last quarter, with $15.5 million cash on hand.

Sen. Susan Collins, R-Maine is defending her seat in a blue state and facing criticism from Democrats over her opposition to cuts included in the GOP’s tax and spending bill. “It’s not an accident that Susan Collins is failing to stop the toxic GOP agenda,” said Tommy Garcia, Maine Democratic Party spokesman.

Texas joins the list amid GOP concerns about Sen. John Cornyn’s, R-Texas, vulnerability in a potential primary against Attorney General Ken Paxton (R). Cornyn lags in early polling despite a strong fundraising record.

“The hard part of running against Ken Paxton … is there are so many things — it’s hard to know which thing you have to center on,” said a GOP strategist.

The open seat left by retiring Sen. Gary Peters, D-Mich., rounds out the list. Democrats are embroiled in a three-way primary between Rep. Haley Stevens, D-Mich., state Sen. Mallory McMorrow (D), and Abdul El-Sayed, backed by Sen. Bernie Sanders, I-Vt.

As President Trump and Republican leaders pursue legislative achievements while Democrats prepare prominent candidates, the 2026 midterm elections are emerging as a critical contest for control of the Senate.