(NewsNation) — With the 2022 midterms just hours away, Senate races in the country’s battleground states look closer than ever.

Today, Democrats control the U.S. Senate by the slimmest of margins — Vice President Kamala Harris serves as the tiebreaking vote in a chamber that’s divided 50-50.

That could all change Tuesday. The GOP is hoping to swing the balance of power by flipping seats in Arizona, Nevada and Georgia, while Democrats are looking to build on their advantage by picking up the GOP-held seat in Pennsylvania.

The Decision Desk HQ forecast model currently predicts that Republicans have a 57.2% chance of controlling the Senate.

Here are the projections in every closely contested Senate race nationwide.

All of the following probabilities are based on Decision Desk HQ’s Senate Election Model as of Monday, Nov. 7.

pennsylvania – john fetterman (d) vs. mehmet oz (R)

Who currently holds the seat? Republicans. GOP Sen. Pat Toomey has held the seat since 2010 but chose not to seek a third term.

Chance of winning: Oz is favored, 59.4%, over Fetterman, 40.6%.

How have the odds changed? As recently as a month ago, Fetterman had a 70% chance of winning the election. That gap closed considerably in recent weeks before flipping in Oz’s favor following the candidates’ one and only televised debate.

What to watch: Fetterman is looking to re-capture the state’s white working class voters who have moved toward the GOP in recent elections. He’ll also be relying on strong turnout among Black voters in the state’s urban center — Philadelphia.

Oz is hoping to secure enough votes from suburban moderates to propel him to victory. He’ll also be counting on support from the pro-Trump wing of the party. Despite receiving the former president’s endorsement, many MAGA Republicans backed Oz’s opponent, Kathy Barnette, in the primary.

georgia – raphael warnock (d) vs. herschel walker (r)

Who currently holds the seat? Democrats. Sen. Raphael Warnock has held the seat since winning a special election runoff in January 2021.

Chance of winning: Warnock is favored, 55.5%, over Walker, 44.5%.

How have the odds changed? Like other Senate races in battleground states, the momentum has been with the Republican candidate over the past month. In early October, Warnock had an 80% chance of winning.

What to watch: Gwinnett County. Once reliably Republican, the region northeast of Atlanta has grown more racially diverse and voted increasingly Democratic in recent elections. Experts say the margin here may indicate which way college educated, moderate voters are leaning in 2022.

“This is one of those counties that really got Joe Biden, Jon Ossoff and Raphael Warnock over the finish line back in 2020,” said Kiel Williams, a senior data scientist at Decision Desk HQ.

nevada – catherine cortez masto (d) vs. adam laxalt (r)

Who currently holds the seat? Democrats. Sen. Catherine Cortez Masto was elected in 2016.

Chance of winning: Laxalt is favored, 55.5%, over Cortez Masto, 44.5%.

How have the odds changed? The race has remained extremely close throughout the cycle. A month ago, Cortez Masto had a 53% chance of winning.

What to watch: Clark County. The region, which includes Las Vegas, accounts for more than 70% of the state’s registered voters. In particular, the results will provide insight into how Latinos are voting this year. Recent research suggests Hispanic voters have been moving right, although it remains to be seen whether that trend remains mostly contained to Florida and South Texas.

“For a Democrat to win statewide in Nevada they have to net enough votes out of Clark County to be able to survive that Republican firewall from the entire rest of the state,” said Williams.

arizona – mark kelly (d) vs. blake masters (r)

Who currently holds the seat? Democrats. Sen. Mark Kelly has held the seat since a special election in 2020.

Chance of winning: Kelly is favored, 66.2%, over Masters, 33.8%.

How have the odds changed? Kelly had an 81% chance of winning in early October. Most recent polls show the incumbent with a slim lead, but that gap has narrowed over the past month.

What to watch: Maricopa County. The most populous county in the state remains one of the most hotly contested anywhere in the nation. Trump carried the county in 2016 before Biden narrowly won it in 2020.

“If we see a scenario in which Democrats aren’t winning Maricopa County, they have almost no path to victory in the state of Arizona,” said Williams.

ohio – tim ryan (d) vs. j.d. vance (r)

Who currently holds the seat? Republicans. GOP Sen. Rob Portman has held the seat since 2010 but chose not to seek a third term.

Chance of winning: Vance is favored, 81.6%, over Ryan, 18.4%.

How have the odds changed? The gap between the two candidates has widened in Vance’s favor over the last month. In early October, DDHQ’s model showed Vance with a 60% chance of winning the seat.

What to watch: A state that used to be considered a true toss-up has become more reliably red in recent elections. Ryan is hoping to reverse that trend by branding himself as a moderate candidate who isn’t afraid to buck the more progressive talking points of his party.

In order to win, Ryan will likely have to outperform Biden in the state’s urban counties in Cincinnati, Columbus and Cleveland, and close the gap in rural areas that overwhelmingly backed Trump.

new hampshire – maggie hassan (d) vs. don bolduc (r)

Who currently holds the seat? Democrats. Sen. Maggie Hassan has held the seat since 2016.

Chance of winning: Hassan is favored, 67.1%, versus Bolduc, 32.9%.

How have the odds changed? A month ago, Hassan had an 80% chance of keeping her seat but that gap has narrowed in recent weeks.

What to watch: In one of the most highly educated states in the country, a Republican victory could be a sign that voters who turned away from Trump are returning to the GOP in greater numbers than expected.

“If we see Maggie Hasson actually losing on election night, then that means Republicans are probably on their way to 53 or 54 Senate seats,” said Williams.