9 Seats Will Determine Which Party Wins Senate

The nine most vulnerable seats in the Senate have been revealed as Democrats look to regain control, The Hill reports.

Democrats need to net four seats. In Tuesday's election, the Democrats will defend 10 seats, while Republicans defend 24 seats, according the Hill.

Here are the Senate seats most likely to flip:

• Illinois Republican Mark Kirk — He "remains at the top of this list as the most vulnerable GOP incumbent this cycle," according to The Hill. Kirk is facing Democratic Rep. Tammy Duckworth.
• Wisconsin Republican Ron Johnson — The Hill notes the Republicans are shooting for a comeback, while Democrats remain confident about their chances with former Sen. Russ Feingold.
• Pennsylvania Republican Pat Toomey — The "race appears to be shifting toward Democrats in the final days," where Toomey is facing off against Democrat Katie McGinty.
• Indiana (Open Seat) — Former Democrat Sen. Evan Bayh is the odds-on-favorite, but recent polls put Republican Todd Young tied or ahead.
• Nevada (Open Seat) — The Hill reports the state offers Republicans the best shot at picking up a seat. GOP Rep. Joe Heck is narrowly leading Nevada Attorney General Catherine Cortez Masto.
• North Carolina Republican Richard Burr — He "is playing defense as he fights for his political life," according to the Hill. Recent polls have teetered back-and-forth between Burr and Democrat Deborah Ross.
• New Hampshire Republican Kelly Ayotte — She has maintained her support after breaking with Donald Trump. Recent polls show her with a slight lead over Democratic Gov. Maggie Hassan.
• Missouri Republican Roy Blunt — The Hill reports Democrat Jason Kander "is on the verge of upsetting" Blunt.
• Florida Republican Marco Rubio — One expert says the race has moved from tossup to leaning toward Rubio over Democrat Patrick Murphy.

• GOP Will Hold Senate With Indiana Win
• Priebus Has Faith GOP Will Hold Senate