On November 3rd, 470 down ballot races taking place across the country will determine the makeup of the 117th Congress.
In the Senate, 35 seats are up for grabs, and Democrats are expected to make gains with the chamber’s majority within clear striking distance.
Democrats currently have 45 seats, along with two independents, compared to the Republicans' 53 seats.
Among the most vulnerable republicans, Sen. Martha McSally, a favorite of President Trump, is going head to head with former space shuttle commander Mark Kelly in Arizona.
In Maine, moderate Republican Susan Collins is fighting for re-election against democrat Sarah Gideon.
And in Colorado, incumbent Senator Cory Gardner is facing a tough challenge from former governor and presidential candidate John Hickenlooper.
But this year, tight races have extended into the typically Republican-friendly south as well, with Democrat Cal Cunningham aiming for Senator Thom Tillis’ seat in North Carolina, Democrat Jaime Harrison looking to unseat Lindsey Graham in South Carolina, and two races in Georgia — one pitting Senator David Perdue against Democrat Jon Ossoff.
Moving west, polls show Iowa Senator Joni Ernst and Theresa Greenfield separated by a razor thin margin, and in Montana, Democratic Governor Steve Bullock is challenging incumbent Senator Steve Daines.
Even in the last frontier, Alaska, Senator Dan Sullivan is fighting a tough challenge from the left, and Democrats have extended their reach into typically reliably deep red states: challenging Texas’ John Cornyn and even Majority Leader Mitch McConnell in Kentucky.
Meanwhile, Democrats are only fending off two key challenges: Alabama, where incumbent Senator Doug Jones could lose to former Auburn University football coach Tommy Tuberville, and Michigan, where Democratic Senator Gary Peters is going head to head with Republican John James.
A blue wave in the Senate could mean a new Majority Leader: Senator Chuck Schumer of New York, who would be the first Democrat to control Congress’ upper chamber in six years.
Across the Capitol, in the House of Representatives, all 435 seats in the House of Representatives come up for re-election every two years, and Democrats are expected to gain several, padding their existing majority, led by Speaker Nancy Pelosi.
Unlike the Presidency — which begins at noon on January 20th — the 117th congress will be sworn in on January 3rd.
If there are significant challenges to the vote or an electoral tie, it could fall to the Congress to determine the next President.