Washington — In the final weeks before the 2024 elections, Senate Democrats are facing an ominous map that leaves them with slim hopes of retaining their majority.

With a 51-49 majority in the upper chamber, Democrats have little room for losses in the 2024 contests. Independent Sen. Joe Manchin’s decision to leave Congress has all but guaranteed a Republican flip in deep-red West Virginia. Democrats are also up for reelection in two states Trump won in 2020. And in another six states, Democrats are fighting to hold onto control.

In contrast, Republicans only have two seats that are considered possible pickup opportunities for Democrats: Texas and Florida, although one more race between an independent and a Republican incumbent has grown surprisingly competitive. 

Here are the key races to watch: 

Ohio Senate race: Bernie Moreno vs. Sherrod Brown

Democratic Sen. Sherrod Brown is fighting to hold onto his seat in the upper chamber, as businessman Bernie Moreno makes a play for the battleground seat in what has been among the most expensive races this cycle.

Moreno, a Trump-backed Republican who has embraced election denialism, won the nomination over more traditional conservatives in the state. The wealthy businessman’s self-funding has helped him keep pace with Brown’s. But Moreno, 57, has recently come under fire for legal troubles related to his automotive business, along with criticism over comments about abortion, creating an opening that Brown’s campaign has worked to capitalize upon.  

The Cook Political Report rates the race as a toss-up. Brown’s Senate colleagues have expended significant effort to support his reelection campaign. But for Brown, 71, who is the only Democrat holding statewide office in Ohio and has been in office since 2007, his reelection may hinge on his ability to separate himself from the top of the ticket in a state that former President Donald Trump won by eight points in 2020.  

Michigan Senate race: Elissa Slotkin vs. Mike Rogers

In Michigan, former Republican Rep. Mike Rogers and Democratic Rep. Elissa Slotkin are vying for Sen. Debbie Stabenow’s long-held seat in the upper chamber. 

Slotkin, 48, has represented Michigan’s 7th District in the House since 2019. The former CIA officer worked in national security-focused posts in both the Bush and Obama administrations and has touted her work across the aisle as a moderate Democrat. 

The Republican nominee, Rogers, is an Army veteran who represented Michigan’s 8th District in the House from 2001 to 2015, and he led the House Intelligence Committee during his last four years in the lower chamber. The 61-year-old also previously worked as an FBI agent and has campaigned on returning to Washington to fix what he sees as the shortcomings of the current administration.

Michigan hasn’t elected a Republican to the Senate in three decades. But this year’s contest is considered among the most competitive of the cycle, with the Cook Political Report rating the race as a toss-up. A CBS News poll showed Slotkin leading in September. 

Maryland Senate race: Larry Hogan vs. Angela Alsobrooks

Prince George’s County Executive Angela Alsobrooks and former Maryland Gov. Larry Hogan are facing off in a race that’s grown unexpectedly competitive in deep-blue Maryland. The race kicked off after Sen. Ben Cardin announced last year that he would retire, teeing up what was expected to be an easy Democratic victory in the state. But Hogan’s late entrance into the race cast that victory into question, making a GOP flip of the seat possible. 

The popular Republican governor, who served from 2015 to 2023, has widespread name recognition in the state and left office with high approval ratings. He’s often set himself apart from his party, being known to criticize former President Donald Trump. And he’s campaigned on working across the aisle for Marylanders, while pledging to be a “pro-choice” Republican. Meanwhile, Democratic groups have highlighted across the airwaves Hogan’s past statements personally opposing abortion and his decision to veto legislation as governor that would have expanded abortion access in Maryland. A victory by Hogan, 68, would mark the first time a Republican has won a Maryland Senate seat in nearly four decades. 

Alsobrooks, a former prosecutor, and her campaign have emphasized that despite Hogan’s bipartisan framing, the seat could dictate control of the Senate, and with it, the ability to spearhead any Democratic priorities. Alsobrooks, 53, would be the first Black woman to represent the state in the Senate, and the fourth Black woman to serve in the Senate in its history. The Cook Political Report has rated the race as a likely win for Democrats.

Nevada Senate race: Jacky Rosen vs. Sam Brown

Democratic Sen. Jacky Rosen is looking to hold onto her seat in the Silver State, facing her first reelection bid in the state that was home to among the closest Senate races in the country in 2022. 

Rosen is facing off against Sam Brown, a 40-year-old businessman and former Army captain. And although Republicans haven’t won a Senate race in the Silver State since 2012, they flipped the governor’s mansion in the last election, suggesting that the state’s races could be in play for the GOP. 

But Rosen, 67, has appeared to have a significant edge over Brown since Vice President Kamala Harris entered the presidential race, after President Biden had struggled to garner support in the state. The Cook Political Report in August changed its rating of the Nevada Senate race from a toss-up to lean Democrat after Harris entered the race, noting that the margin that Senate candidates in battleground states now have to outperform the top of the ticket has shrunk, and has been especially pronounced in Nevada. 

Texas Senate race: Ted Cruz vs. Colin Allred

Once considered a long-shot Democratic bid in the red state, Rep. Colin Allred has launched a formidable challenge against Sen. Ted Cruz for his seat in the upper chamber. 

Cruz, 53, has been in the Senate since 2013 and has widespread name recognition in the Lone Star State and nationally, having launched a bid for the White House in 2016. He’s worked to tie Allred to national Democrats and paint his positions as extreme.

Allred, 41, has represented Texas in the House since 2018, when he flipped a long-held GOP district in the Dallas area. Once a linebacker for the Tennessee Titans, the former football player came to Congress after working as a civil rights attorney. Allred has criticized Cruz’ record and argued he doesn’t pull through for Texans.

No Democrat has won a statewide election in Texas since 1994, and the Cook Political Report rates the race as lean-Republican. But Texas remains among Democrats’ best pickup opportunities in the upper chamber. 

Arizona Senate race: Ruben Gallego vs. Kari Lake

Democratic Rep. Ruben Gallego and Republican Kari Lake are duking it out for Sen. Kyrsten Sinema’s seat in the upper chamber, after the first-term independent opted not to seek reelection, facing an uphill climb in the battleground state. 

Gallego, 44, is a former Marine who was first elected to the House in 2014 and represents a district that includes parts of Phoenix and Glendale. The progressive lawmaker has worked to court voters in the middle, while Lake, who narrowly lost a hard-right campaign for governor in 2022, has worked to do the same.

Lake, 55, is a former news anchor and close ally of former President Donald Trump. She has been a vocal election denier regarding the outcome of  both her gubernatorial race and Trump’s 2020 matchup against President Biden. But Lake has tried to reel in her message during the Senate campaign, albeit inconsistently, earning the backing of the party’s reluctant establishment along the way. 

The Cook Political Report ranks the race as leaning toward Democrats. Before Sen. Kyrsten Sinema won her Senate race in 2018, a Democrat hadn’t won a Senate seat in Arizona in three decades. Sinema left the Democratic Party in 2022.

Montana Senate race: Tim Sheehy vs. Jon Tester

Considered among the most endangered Democrats this cycle, Sen. Jon Tester is fighting to keep the Senate seat he’s held for nearly two decades. And although he’s fended off previous challenges as a moderate in deep-red Montana, the state’s shifting demographic has Republicans feeling optimistic about their pickup opportunity in the Big Sky State. 

Tim Sheehy, a former Navy SEAL and founder of an aerial firefighting company, is facing off against Tester and has tried to draw a contrast as an outsider, while painting Tester as an establishment candidate with deep ties to Washington. But Sheehy, 38, has faced criticism for lacking the roots that Tester has in the state, along with discrepancies in his story of how he sustained a gunshot wound.

For Tester, 68, the influx of new residents in the state, made up largely of Republicans, has posed trouble for the only Democrat serving in statewide office in Montana, and adds to a dominant showing by the GOP in the state in the last two elections, where Tester bucked trends by hanging onto his seat. But whether he can withstand the GOP headwinds this year remains to be seen, with the Cook Political Report ranking the race as lean Republican.

Pennsylvania Senate race: Bob Casey vs. Dave McCormick

Dave McCormick is working to unseat Democratic Sen. Bob Casey, who’s been in the Senate since 2007, in battleground Pennsylvania. 

McCormick, 59, is a combat veteran and former chief executive of a major hedge fund who also sought the Republican nomination to represent Pennsylvania in the Senate in 2022, when he lost to Mehmet Oz. He’s campaigned on being a change agent to the status quo, billing Casey as an establishment politician. And he’s drawn a line between his position on abortion and Casey’s, which he calls “extreme.” McCormick opposes abortion except in the case of rape, incest or to save the life of the mother, while also arguing that the issue should be left up to states and opposing a national abortion ban. Casey — who once called himself a “pro-life Democrat” — now supports the protections under Roe v. Wade, which guaranteed a right to abortion prior to fetal viability. 

Seeking a fourth term in the upper chamber, Casey, 64, is a former state auditor general and treasurer. The son of former Pennsylvania Gov. Bob Casey Sr., he’s an institution in the Keystone State and has a reputation as a moderate Democrat. Casey has billed his opponent as an out-of-touch carpetbagger, hammering McCormick over his previous Connecticut residency.

The Cook Political Report rates the race as a tossup, changing it from lean Democrat on Oct. 21. CBS News poll showed Casey leading in September. 

Wisconsin Senate race: Tammy Baldwin vs. Eric Hovde

Democratic Sen. Tammy Baldwin is seeking a third term in the Senate, facing a challenge from  Republican Eric Hovde in the Badger State. 

Baldwin, 62, was first elected to the Senate in 2012 after representing Wisconsin in the House for more than a decade. Baldwin, the first openly LGBTQ+ Senator in history, has a long history of courting rural voters in the state, winning counties that Trump previously won in the 2018 election, despite her progressive politics. 

Hovde, 60, also sought the GOP nomination in 2012. His bid fell short to former Wisconsin Gov. Tommy Thompson, who went on to lose the election to Baldwin. The businessman with deep pockets is one of a number of Republican Senate candidates recruited in part for their ability to fund their own campaigns this cycle. 

Hovde has campaigned on issues like immigration, while criticizing Baldwin for her record in Washington. Meanwhile, Baldwin has billed Hovde as an out-of-touch wealthy businessman as the two spar over the seat in the battleground state. The Cook Political Report rates the race as a toss-up, shifting its rating from lean-Democrat on Oct. 8. A CBS News poll showed Baldwin leading in September. 

West Virginia Senate race: Jim Justice vs. Glenn Elliott

Senate Democrats have all but ceded Sen. Joe Manchin’s seat to Republicans after he announced he wouldn’t seek reelection in the red state. Democrat Glenn Elliott, a former mayor of Wheeling, West Virginia, is facing off against current Republican Gov. Jim Justice, who is almost guaranteed a win in the Mountain State. 

Even before Manchin left the race, the seat was expected to pose a challenge for Democrats once the popular GOP governor entered the race. Senate Minority Leader Mitch McConnell himself encouraged Justice to run and seize the opportunity to unseat Manchin, who formerly served as governor and has represented West Virginia in the Senate since 2010. Manchin, a moderate who has often been a thorn in the side of Democratic leadership, opted to leave the party and register as an independent in May.

The Cook Political Report rates the race as solid Republican.

Nebraska Senate race: Deb Fischer vs. Dan Osborn

Sen. Deb Fischer’s reelection appeared guaranteed until just weeks before the election, when a string of polls revealed a surprisingly competitive race between the incumbent and independent Dan Osborn. 

Osborn, a Navy veteran, mechanic and union leader, has received an onslaught of outside funding, forcing Republicans to redouble their efforts in a race that was thought to be an easy win. The 49-year-old independent is a political newcomer who’s leaned into a populist message, while billing his opponent as an establishment politician controlled by corporate interests.

Fischer is seeking a third term in the Senate, where she served on the powerful armed services and appropriations committees. The 73-year-old, who has a background as a cattle rancher, has leaned on an endorsement from Trump in recent weeks, while painting her independent opponent as a “Democrat in disguise.” Osborn has pledged not to caucus with either Democrats or Republicans in the Senate.

The Cornhusker State is home to nearly twice as many registered Republicans as Democrats, and Trump won Nebraska by nearly 20 points in 2020. But Nebraska is also home to nearly as many nonpartisan voters as Democrats. And with no Democrat in the race, the two voting groups could come together to launch a formidable challenge against the Republican incumbent. The Cook Political Report rates the race as lean Republican, moving it from likely Republican on Oct. 21.