10 senators are at risk of losing reelection. It may be enough to give Democrats a majority in Congress.

Sen. Susan Collins is facing off against State House Speaker Sara Gideon in Maine.

Collins has historically positioned herself as an independent, moderate, conservative-leaning senator. She has been a proponent of LGBT rights and abortion access, and was ranked in 2019 as the most bipartisan member of the U.S. Senate by the Lugar Center at Georgetown University.

Collins was highly popular for much of her career but has seen her favorability decline since Trump's election in 2016. President Trump's brand of politics lacks bipartisan support in congress, making it increasingly difficult for Collins to toe the bipartisan line as she would in the past.

A September Quinnipiac University survey showed that Gideon currently holds a 12 percentage point lead in the polls over Collins in a 54%-42% split among likely voters. Gideon's lead appears to be increasing as polling from August by Quinnipiac University had Gideon up by just 4 points.

"The tide has turned on Senator Susan Collins, who was so popular in Maine that she won nearly 70 percent of the vote the last time she ran. Likely voters are sending the message that there's no 'middle of the road' when it comes to President Trump, who is deeply unpopular in the state," said Quinnipiac University Polling Analyst Mary Snow.

Sen. Doug Jones is squaring this November against former Auburn University football coach and Republican, Tommy Tuberville.

Jones was elected in a 2017 special election following the resignation of Republican incumbent Sen. Jeff Sessions to become attorney general. Jones faced off against Judge Roy Moore, a former Alabama Supreme Court Justice.

Moore was accused of sexual assault by eight women when they were in their teenage years and was previously expelled from the Alabama Supreme Court on two separate occasions, which proved to be easy fodder for Democrats to use against Moore in the election. Still, Jones only defeated Moore by 1.5% percentage points in a 49.9%-48.4% split of the vote, according to The New York Times.

Tuberville was endorsed by President Donald Trump, which helped him defeat his predecessor, Jeff Sessions, in the 2020 GOP primary. As the head football coach at Auburn University from 1999-2008, Tuberville led the team to 85 wins and 40 losses.

According to a Decision Desk HQ election forecast, there is an 80.9% chance that Tuberville will defeat Jones. With less than two months remaining until the November election, Jones is winning just 35% of likely voters, according to a Morning Consult poll released at the beginning of September. The survey shows that 52% of likely voters support Tuberville.

Sen. Lindsey Graham is locked in a dead heat with Democrat Jamie Harrison in South Carolina, according to a recent poll from Quinnipiac University.

Graham has been in the Senate since 2003 and was preceded by Sen. Strom Thurmond. He is the current chair of the Senate Judiciary Committee. Harrison, his challenger, is a former state senator and the former chairman of South Carolina's Democratic Party.

According to the Post and Courier, Graham has been outraised by Harrison over the past two fundraising quarters.

A mid-September Quinnipiac University poll shows the two candidates tied 50%-50% amongst likely voters. Harrison's campaign is fueled by his unique campaign style and charisma.

Additionally, Fox News extensively blamed Graham for encouraging President Donald Trump's interviews with esteemed journalist Bob Woodward. The interviews included an exchange which showcased the president's cover-up of the by the Saudi Arabian government's murder of journalist Jamal Khashoggi.

"A victor by almost 16 points back in 2014, Senator Graham stares down the first real test of his Senate tenure. Outspent and accused by some of being a Trump apologist, he is in a precarious tie," said Quinnipiac University Polling Analyst Tim Malloy.

First-term incumbent Sen. Thom Tillis and Democrat Cal Cunningham are currently vying for a Senate seat in North Carolina.

Tillis, who was first elected to the U.S. Senate in 2014, is the former speaker of the North Carolina House of Representatives and currently sits on the Judiciary and Armed Services Committees.

Cunningham is a U.S. Army veteran and North Carolina state legislator. He's gained support through his plans to increase healthcare access, combatting climate change, and investing in the country's educational system.

A September poll of likely voters by Benenson Strategy Group and GS Strategy Group shows Cunningham ahead of Tillis by three percentage points. Additionally, polling from the New York Times and Sienna College has Cunningham up by 5 percentage points. As of mid-September, Decision Desk HQ forecasts a 67.8% chance of Cunningham defeating Tillis in the Senate.

Senate Majority Leader Mitch McConnell is currently facing off against U.S. Marine Corps veteran Amy McGrath in Kentucky.

Sen. McConnell has been a member of the U.S. Senate since 1985. Before his time in the Senate, he was the Jefferson County Judge/Executive. McGrath is a veteran with previous congressional aspirations, having failed to win a seat in the U.S. House of Representatives in 2018.

While she has the support of many in the state, McGrath has drawn ire from her Democratic peers from confusing messaging about Supreme Court Justice Brett Kavanaugh and McConnell's ability to assist with President Trump's agenda.

Federal election filings show the race between McConnell and McGrath is the most expensive senate race of 2020. McGrath has raised close to $47 million for her campaign, while McConnell has raised $36.7 million. Each candidate has a little over $16 million left to spend on the election.

According to a recent Quinnipiac University survey of likely voters, McConnell is polling 12 percentage points higher than McGrath in a 53%-41% split among legal voters.

"After 36 years in the Senate, Majority Leader McConnell appears to have a comfortable path to six more years in Washington in one of the most expensive Senate races to date," said Quinnipiac University Polling Analyst Tim Malloy.

First-term Sen. David Perdue is facing Democrat Jon Ossoff for a Senate seat in Georgia.

Perdue, the former CEO of Reebok as well as the former CEO and chairman of Dollar General, was first elected in 2014 in a Republican wave year.

Ossoff is a business owner and investigative journalist who previously ran for a highly-contested House seat in a special election against Karen Handel. After narrowly losing to Handel in 2017, Ossoff set his sights on the Senate where he won this year's highly-competitive Democratic primary.

In late July of 2020, Perdue's campaign ran a blatantly anti-Semitic ad against Ossoff which enlarged his nose and placed him next to Senate Minority Leader Chuck Schumer and insisted the two were trying to "buy Georgia." Perdue and his campaign denied any affiliation with the creation of the ad and insisted that it was created by an outside vendor.

The suburbs of Atlanta have recently begun trending more blue, leading experts to believe that Georgia is become much more at play for Democrats than previously expected. In a recorded call from April with "Women for Trump" obtained by CNN, Perdue noted the state's ongoing political shift.

"Here's the reality: The state of Georgia is in play," said Perdue. "The Democrats have made it that way."

The most recent September survey of 800 likely voters from Fabrizio Ward & Hart Research, a Republican-leaning polling group, shows Ossoff with a 1 percentage point advantage over Perdue. A mid-September forecast by Decision Desk HQ has Perdue with a 56.9% chance of defeating Ossoff.

Sen. Martha McSally is fighting for her political life in a special election against Democrat Mark Kelly.

McSally joined the Senate in 2019 following the passing of longtime congressman, Sen. John McCain. She first ran for a Senate seat in the 2018 election to fill the seat of outgoing Sen. Jeff Flake, but lost to Democratic nominee Kyrsten Sinema by 2.4 percentage points.

McSally's Democratic challenger, Mark Kelly, is an astronaut and the husband of former congresswoman Gabrielle Giffords who was shot in the head in 2011 in Tucson.

While McSally is an accomplished fundraiser, she was outraised by Kelly in the second quarter of 2020. According to federal campaign filings, Kelly has outraised McSally by $15 million during his campaign. In an attempt to fundraise, McSally drew the ire of some by asking her supporters to "fast a meal" and donate the money to her instead.

A mid-September survey of likely voters from Monmouth University shows Kelly ahead of McSally by four percentage points in a 50%-46% split of the poll. According to a Decision Desk HQ forecast, Kelly currently has a 74.2% chance of beating McSally in November.

First-term incumbent Sen. Joni Ernst matches up against Democrat Theresa Greenfield in Iowa.

Ernst was originally elected in 2014 amid a GOP wave in Congress. She is a veteran of the Iowa Army National Guard and gained a national following during her first Senate run with advertisements promising to "make 'em squeal" in Washington. Her challenger, Greenfield, is real estate developer and urban planner making her first official run as a political candidate.

Sen. Ernst recently drew negative attention by announcing her skepticism of the 190,000 reported COVID-19 deaths in the United States. She said she thought there may be fewer than 10,000 deaths, a suggestion for which she privately apologized to the Iowa Medical Society, but has yet to publicly retract.

According to an election forecast from Decision Desk HQ in mid-September, Ernst has a 56.3% chance of staying in Congress for a second term. A recent survey of likely voters by Fabrizio Ward and Hart Research Associates, a Conservative-leaning pollster, has Ernst up by five percentage points in the polls over Greenfield.

First-term incumbent Sen. Cory Gardner squares off against Democrat and former Colorado Governor John Hickenlooper.

Before joining the Senate, Gardner spent time in the U.S. House of Representatives, as well as the Colorado House. During his time in the Senate, he has had a heavy focus on energy policy and public lands — two of the state's most pressing issues.

Gardner's challenger, Hickenlooper, is the former mayor of Denver and spent eight years as the governor of Colorado. While popular during his time in office, Hickenlooper drew little interest or support during a failed run for the Democratic presidential nomination, which came to a halt in 2019. Despite having joined the Senate race later than most, Hickenlooper won the Democratic primary by 17.4 percentage points of the vote.

An early-September survey of likely voters by Fabrizio Ward and Hart Research Associates, a Conservative-leaning polling group, shows Hickenlooper with a five percentage point lead over Gardner of the survey's 51%-46% split. Forecasting by Decision Desk HQ has Hickenlooper with 78.2% chance of defeating Gardner in November.

Alaska Sen. Dan Sullivan is vying to hold onto his Senate seat against independent candidate Dr. Al Gross.

Sullivan was elected in 2014 amidst a Republican wave in the Senate. He formerly worked as a clerk in several state and federal courts and is a veteran of the U.S. Marine Corps. He is an active member of the US Marine Corps Reserves and currently sits on the committees on Veteran Affairs; Environment and Public Works; Armed Services; and Commerce, Science, and Transportation.

Gross is an orthopedic surgeon, fisherman, and affordable healthcare advocate. While running as an independent, Gross would caucus with the Democratic Party if elected. Gross' campaign has focused on admonishing Sen. Sullivan for failing to protect the US Postal Service and for failing to support anti-climate change initiatives.

A recent survey from Public Policy Polling shows the two candidates tied amongst Alaska voters, with 14% of respondents undecided. According to Decision Desk HQ, Sullivan has a 69.1% chance at retaining his Senate seat against Gross.

Grace Panetta contributed reporting.