Final Senate rankings: 5 seats most likely to flip

Two days remain until Election Day, and Republicans are aiming to take control of the Senate and expand their majority.

Democrats hold a 51-49 advantage, which Republicans have already sliced into with their pending victory in West Virginia. That leaves them needing only one more seat to win back the upper chamber, with Montana and Ohio being the prime targets.

According to Decision Desk HQ (DDHQ), the GOP has a 70 percent chance of wrestling back the Senate. 

A number of battleground races have tightened to dead heats, and the performance of former President Trump and Vice President Harris could also play a role in the outcomes.

For the final time of the 2024 cycle, here are the top five seats likely to flip: 

Montana 

A win in Montana means the majority for the GOP, and the party has felt increasingly bullish that Republican Tim Sheehy is in position to topple Sen. Jon Tester (D-Mont.).

Montana is widely considered Republicans’ best chance at flipping a seat, outside of West Virginia.

According to a recent survey by The Hill/Emerson College, Sheehy leads by 4 percentage points (50 percent to 46 percent) over the three-term incumbent. And the Cook Political Report has the seat in its “lean Republican” column.

Perhaps more indicative of where the race stands is how each side has maneuvered their final spends. A top GOP outside group recently shifted nearly $3 million from Montana to Nevada, where Republicans have seen some last-minute tightening, showing confidence that Sheehy is ready to seal the deal. 

“I'm feeling certain about Montana right now,” one Senate Republican told The Hill, noting that recent internal polls on the GOP side have shown Sheehy holding a lead over Tester that is outside the margin of error. 

Democrats, however, don’t think this race is over despite the public polls. They are quick to note that Montana is notoriously difficult to poll and say that Tester’s 2012 victory, his last run in a presidential year, shows he can win despite polls showing him down.

Ohio

The race between Sen. Sherrod Brown (D-Ohio) and Republican Bernie Moreno has drawn to even with Tuesday fast approaching.

A win in Ohio would expand Republicans’ majority and the race has become the most expensive contest on the Senate map this year.

Brown held a steady lead that lasted through Labor Day, buoyed by a massive advantage on the airwaves, but the wind appears to be at Moreno’s back now. An average of polls from DDHQ and The Hill shows Moreno up by just less than 1 percentage point.

Republican operatives have argued that the contest is mirroring the trend line of Sen. JD Vance’s (R-Ohio) race two years ago. Vance trailed then-Rep. Tim Ryan (D-Ohio) throughout the summer and into October before overtaking and ultimately defeating him by 6 points.

They are also counting on a boost from Trump. The operatives say an 8-point victory at the presidential level should be enough to pull Moreno across the finish line.

Brown himself has reportedly told donors that an 8-point margin is one that he likely cannot overcome.

“Sherrod's an A [candidate] and Bernie's a C-,” one GOP operative involved in Senate races said. “But we should win it based on gravity.” 

The Ohio contest is set to become not only the most expensive Senate race this cycle, but of all time. The Georgia Senate race in 2020 between Sen. Jon Ossoff (D) and former Sen. David Perdue (R) attracted $412 million, with this contest set to eclipse the $500 million mark. 

Wisconsin

Sen. Tammy Baldwin (D-Wis.) is trying to hang on for dear life as Republican Eric Hovde has brought the must-win race for Democrats to a virtual dead heat. 

Republicans are eyeing Wisconsin as one of their best pickup opportunities outside of Montana and Ohio.

Baldwin, a two-term incumbent, ran ahead of Hovde throughout much of the cycle, but that lead has largely disappeared as GOP-leaning men have come home to the Republican Party. The Cook Political Report rates the contest a “toss-up.”

Still, whether Hovde can get over the final hump remains a major question. According to the final Marquette University Law poll, Baldwin holds a 2-point lead over the GOP nominee. Perhaps just as important, she is outrunning Harris by a slight margin. 

Democrats still see work to do in the home stretch, and that centers on turning out Democratic-heavy Milwaukee.

“I think you'll see a real focus on the city of Milwaukee from Democrats up and down the ballot in the final hours,” one Wisconsin-based Democratic operative said, pointing to Harris’s rally with Baldwin in the city on Friday and other smaller events.

Republicans, meanwhile, see Baldwin as a generic Democrat who will have trouble separating herself from the top of the ticket despite what the Marquette poll says. 

The race, much like several of the "blue wall” states, also depends on the margin at the top of the ticket, with Hovde likely needing Trump to win with a big enough margin to carry him across the line. 

Pennsylvania

Defeating Sen. Bob Casey (D-Pa.) has been atop the wish list of Pennsylvania Republicans ever since he knocked off Sen. Rick Santorum (R-Pa.) nearly two decades ago, and they easily have their best chance this week.

Casey has held a consistent margin over Republican David McCormick into September, but has seen his lead sliced and diced to where it is now — almost deadlocked. 

While Republicans routinely note that toppling Casey is by no means easy, they laud McCormick and his team for how they’ve been able to tie the Democrat to Harris. 

The perceived inability to create separation is giving Democrats anxiety as they near the end. 

“I always thought Casey would do like 3 points better than the top of the ticket. But polling isn’t showing that. His numbers are the same as Kamala’s,” one senior Pennsylvania Democrat said. “I’m surprised.” 

“Even [Rep. Elissa Slotkin (D-Mich.)], who isn’t an incumbent, is running better than Bob and has some separation with Harris,” the Democrat continued, saying if Trump wins Pennsylvania "by 1 then the Senate race could definitely go Republican too.”

According to Decision Desk HQ, Casey leads by more than 2 percentage points and has a 72 percent chance at nabbing a fourth term. 

Republicans are also putting more muscle behind their message in the final stretch as they spent $16.2 million last week compared to $11.9 million by Democrats in the second most expensive Senate race on the map this cycle. 

Michigan

For a time this fall, Republicans had believed that Michigan represented the party’s best chance at winning a non-Montana or non-Ohio race. 

Unlike races in Pennsylvania, Wisconsin and Nevada, the contest between former Rep. Mike Rogers (R-Mich.) and Slotkin does not feature an incumbent after Sen. Debbie Stabenow (D-Mich.) decided against seeking a fifth term, theoretically giving the GOP an advantage not seen elsewhere. 

However, Slotkin and Michigan have proved a tough nut to crack. 

Operatives on both sides of the aisle have acknowledged in recent days that while the “blue wall” states of Pennsylvania, Wisconsin and Michigan are all up for grabs, Michigan is probably the least likely of the three to flip as the other states have narrowed more in the final weeks. 

“Democrats in Michigan can win just if they hit their numbers,” one GOP operative involved in Senate races said. “We can be perfect in Michigan, but if they hit their numbers, we lose.” 

Slotkin holds a 3.2-percentage point lead over Rogers, with Harris performing better there than in either of the two other states, according to Decision Desk HQ. 

And no Republican has won a Senate race in the Wolverine State in 30 years.