6 months to midterms: The Senate seats that could tip the balance of power

"There's no doubt the climate has gotten more and more difficult by the day," Scott, R-S.C., acknowledged in a recent Fox News Digital interview. But he emphasized he remains "incredibly optimistic" heading into the midterms as he defends the GOP's Senate majority.

Republican Sen. Susan Collins is running for re-election for a sixth six-year term in blue-leaning Maine.

But Collins, who has long been a top DSCC target, has proven tough to beat.

Republican groups supporting Collins are already blasting Platner over controversial comments he made over a decade ago on Reddit about rape, and a well-publicized tattoo on his chest that resembled a Nazi symbol.

Republicans are defending an open seat in the southeastern battleground state, with GOP Sen. Thom Tillis retiring at the end of this year.

Democrats landed their top recruit when former two-term Gov. Roy Cooper launched a Senate campaign last summer. Cooper enjoys tons of name ID in North Carolina and is 6-0 when running statewide races.

Republicans are rallying around former Republican National Committee (RNC) Chair Michael Whatley, who has the president's backing.

Democrats scored another major recruiting victory when former longtime Sen. Sherrod Brown announced he would challenge Republican Sen. Jon Husted.

A former lieutenant governor, Husted was appointed to the Senate a year ago after then-Sen. JD Vance stepped down to serve as vice president.

Ohio, once a premier general election battleground, has turned red over the past decade, and Democrats view Brown as their only competitive candidate in the race to serve the final two years of Vance's term.

Brown lost re-election in 2024 by roughly four points while Trump carried Ohio by 11 points.

But the Cook Report last month shifted its ranking from lean Republican to toss-up, noting that "even recent GOP polling" has indicated the race is all knotted up.

Republicans view first-term Sen. Jon Ossoff as the most vulnerable Democrat seeking re-election in 2026.

But Ossoff has built a massive war chest while the GOP faces a nasty three-way primary battle for its nomination in the crucial southeastern battleground state.

The Cook Report recently shifted the race in Georgia from toss-up to lean Democrat.

The GOP's aiming to flip an open seat in battleground Michigan, where Sen. Gary Peters is retiring.

Former Rep. Mike Rogers, who won the 2024 GOP Senate nomination in Michigan but narrowly lost to Rep. Elissa Slotkin, is making a second straight bid and is the all-but-certain GOP nominee.

Democrats are dealing with a three-way fight between center-left Rep. Haley Stevens, state Sen. Mallory McMorrow, a self-described "pragmatist," and progressive physician Abdul El-Sayed, who is backed by Sanders.

The primary has already exposed numerous Democratic Party divisions and provided Rogers, who is backed by Trump, with plenty of ammunition, and the nominee won't be decided until August.

Democrats were given a big boost in the red-leaning state when former Rep. Mary Peltola announced in February that she would challenge GOP incumbent Sen. Dan Sullivan.

Peltola lost re-election 15 months ago in the at-large district that covers the entire state by three points, while Trump carried Alaska by 11 points.

Longtime Republican Sen. John Cornyn of Texas is in the middle of a competitive and combustible GOP nomination runoff battle against state Atty. Gen. Ken Paxton.

Trump, to date, has stayed neutral in the runoff, which will be held in late May.

The Democrats, who are eyeing the seat in the right-leaning state, nominated state Rep. James Talarico, a rising star in the party.

Talarico hauled in an eye-popping $27 million in fundraising the first three months of this year.

Republicans are hoping to flip the long-held Democratic Senate seat in New England's only swing state, thanks to the retirement of Sen. Jeanne Shaheen, the first woman in the nation's history to be elected governor and senator.

Four-term Rep. Chris Pappas is expected to capture the Democratic Senate nomination in the state's early September primary.

There's a primary race on the Republican side between two former senators seeking a return to Capitol Hill. Former Sen. John E. Sununu, an older brother to former Gov. Chris Sununu, has the backing of the president and has a double-digit lead in public polling. But Trump's first-term ambassador to New Zealand, former Sen. Scott Brown, remains in the race.

Republicans are defending an open seat in Iowa, a onetime swing state that's shifted to the right over the past decade.

But the GOP has rallied around Rep. Ashley Hinson, who is backed by Trump, in the race to succeed retiring Republican Sen. Joni Ernst.

Hinson, a former local TV news anchor who flipped a Democratic-held seat in 2020, is seen as a rising star in the party.

Democrats have a contested primary that includes state Rep. Josh Turek, a Paralympian, and state Sen. Zach Wahls.

Republican Sen. Ashley Moody, who as Florida's attorney general was appointed by Gov. Ron DeSantis last year to fill the seat once held by now-Secretary of State Marco Rubio, is the all but certain Republican nominee.

Moody will likely face off in November against Democratic challenger Alex Vindman, a retired Army lieutenant colonel, whistleblower in the 2019 Trump-Ukraine controversy and brother of Rep. Eugene Vindman.

Recent polling suggests a competitive race between Moody and Vindman in right-leaning Florida.

The retirement of Democratic Sen. Tina Smith is giving the GOP hopes they can flip the seat in the blue-leaning state.

And the NRSC landed what they say is a top-tier recruit in former NBC sports reporter turned conservative pundit and activist Michele Tafoya, who is part of a crowded GOP field.

Minnesota Lt. Gov. Peggy Flanagan, a progressive, is facing off against more moderate Democratic Rep. Angie Craig, who appears to have the backing of Senate Minority Leader Chuck Schumer, D-N.Y., in the race for their party's nomination.