With barely a week until Election Day, the latest aggregates of polling reveals several key Senate races that could decide which of the two major parties will maintain control of the upper chamber for at least the next two years.

Coming into the elections, the Democrats needed to pick up only five seats to keep a Senate majority.

However, the newest revelations in Hillary Clinton’s ongoing email saga have led forecasters to scrutinize their predictions as multiple races show candidates winning by five points or less.

Here’s a look at key Senate races:

New Hampshire: Ayotte vs. Hassan

Wikimedia Commons

Kelly Ayotte (Wikimedia Commons)

Gov. Maggie Hassan, a Democrat, is challenging first term Republican Sen. Kelly Ayotte in a battle where polls separate the two by just 2.5 percent. Ayotte has distanced herself from Trump in the rare woman vs. woman matchup that could go down to the wire.

North Carolina: Burr vs. Ross

Wikimedia Commons

Richard Burr (Wikimedia Commons)

Democrat Deborah Ross, a former Duke Law professor, is challenging incumbent Republican Sen. Richard Burr in a battle where polls separate the two by just 1.6 percent. Burr recently had to apologize for a comment suggesting a “bulls-eye” on Hillary Clinton, who leads the presidential race in N.C. in an important battleground race.

Pennsylvania: Toomey vs. McGinty

AP Photo/Matt Rourke, File

Katie McGinty (AP Photo/Matt Rourke)

Democrat Katie McGinty, a former Clinton administration official, is challenging incumbent Republican Pat Toomey in a battle where polls separate the two by just 5 percent. McGinty has championed environmental progressivism and supports a federal minimum wage of $15 an hour.

Indiana: Young vs. Bayh

Evan Bayh (AP Photo/Michael Conroy)

Evan Bayh (AP Photo/Michael Conroy)

Democrat Evan Bayh, a former three-term U.S. senator, is challenging incumbent Republican Todd Young in a battle where polls separate the two by just 2.3 percent. It was supposed to be a big win for Bayh and the Democrats, but scandals involving his previous use of taxpayer money have dogged the campaign.

Missouri: Blunt vs. Kander

(AP Photo/Reed Hoffmann)

Jason Kander with Sen. Elizabeth Warren (AP Photo/Reed Hoffmann)

Democrat Jason Kander, Missouri’s secretary of state, is challenging Republican incumbent Roy Blunt in a battle where polls separate the two by just 1.5 percent. The 35-year-old Kander is making some waves in the Democratic Party with his inspiring story that includes time spent as a military intelligence officer in Afghanistan.

Nevada: Heck vs. Cortez Masto

Catherine Cortez Masto (Steve Marcus/Las Vegas Sun via AP)

Catherine Cortez Masto (Steve Marcus/Las Vegas Sun via AP)

Democrat Catherine Cortez Masto, Nevada’s attorney general, is challenging Rep. Joe Heck for Sen. Harry Reid’s open seat in a battle where polls separate the two by just 1.7 percent. Cortez Masto would be the first Latina elected to the U.S. Senate, and in recent days she has blasted her opponent for at first supporting Donald Trump, and then disavowing the mercurial businessman following allegations of sexual assault.

Florida: Rubio vs. Murphy

Marco Rubio (AP Photo/Lynne Sladky)

Marco Rubio (AP Photo/Lynne Sladky)

Democrat Patrick Murphy, a memer of U.S. Congress, is challenging incumbent Republican Marco Rubio in a battle where polls separate the two by just 4.4 percent. Rubio is facing criticism following his failed bid for the Oval Office and for promising to return to the private sector, before eventually backing Donald Trump and jumping back in the Senate race.