Election Day is finally here and all eyes are on US Senate races as control of the chamber hangs in the balance.

34 seats are up for election this year: Republicans need to pick up one seat to win the Senate majority. (Ballotpedia)

Could they pull it off? Per FiveThirtyEight, Republicans are "slightly favored" to flip the Senate.

Wait, but what about the red wave? Polling suggests that candidate quality is hampering GOP chances in key states.

Republicans are also defending seats in Wisconsin and Pennsylvania, both of which voted for Biden in 2020.

Split ticket voting is also making Senate races in Pennsylvania and Georgia unpredictable. (FiveThirtyEight)

Want to know which Senate races to watch? Here are five Senate races that will decide the Senate majority in 2023.

1. In Pennsylvania, Democrat John Fetterman and Republican Mehmet Oz are facing off for the state's open Senate seat.

Pennsylvania's open seat was previously held by GOP Sen. Pat Toomey, who announced his retirement in Oct. 2020.

Fetterman entered the race with a modest lead: in Sept., he led Oz by an avg. 10.7 points in the polls. (FiveThirtyEight)

Oz has since closed his gap with Fetterman: as of Mon., he trails Fetterman by an average 0.1 points in the polls. (FTE)

Could Fetterman flip the seat? The odds are in his favor: a late Oct. NYT/Siena poll showed him leading Oz 49%–44%.

2. Nevada Sen. Catherine Cortez Masto is facing a tough re-election bid in the face of a statewide red sweep.

Masto is this cycle's most vulnerable Democratic incumbent: as of Mon., she trails the polls by an avg. 1.4 points. (FTE)

Former state AG Adam Laxalt, the grandson of former Nevada GOP Sen. Paul Laxalt, is challenging Masto for the seat.

The race is locked in a dead-heat: an Oct. NYT poll showed Laxalt and Masto polling evenly at 47%.

Could Laxalt win? Well, not so fast: per FiveThirtyEight, Nevada's polling has a "history of underestimating Democrats."

Masto has also consistently out-raised Laxalt: in Oct., she raised $9.1M+, four times that of Laxalt. (NI)

3. Georgia will once again be at the center of the political universe as Sen. Raphael Warnock fights for a full term.

Warnock flipped the seat in 2021's special election runoff, making history as Georgia's first Black U.S. Senator. (AP)

Warnock is the second most vulnerable Democrat this cycle: as of Mon., he trails the polls by an avg. 1 point. (FTE)

Challenging Warnock for the seat is Republican Herschel Walker, whose campaign has been beset by a series of scandals.

Walker has been accused by several women of pushing them into obtaining abortions. (CNN)

Could Walker win? According to FiveThirtyEight's forecast, the race is in a "dead heat."

4. Arizona Sen. Mark Kelly could cruise to re-election after leading most statewide polls this cycle.

According to FiveThirtyEight's poll average, as of Mon., Kelly is leading GOP challenger Blake Masters by 1.5 points.

An Oct. NYT poll also showed Kelly leading Masters by six points—the biggest lead among battleground states this cycle.

The race could still come down to the wire: per FiveThirtyEight's forecast, Kelly is "slightly favored" to win.

5. New Hampshire Sen. Maggie Hassan is also facing a competitive re-election bid in a red environment.

Republican Don Bolduc has closed the gap in the polls, trailing Hassan by an average 2.2 points, as of Mon.. (FTE)

Bolduc could get carried over by GOP Gov. Chris Sununu, who led an Oct. Emerson College poll by 13 points. (FTE)

According to FiveThirtyEight's forecast, Hassan is "favored" to win with a 77 in 100 chance.