As voters cast their ballots across the country, the number of tight races makes it all but inevitable that some contests won't be called on Election Night -- in several states and districts, the vote count could drag into the wee morning hours of Wednesday, and at least one might not be decided until late November, even December.
Here are just five races that could keep the midterm drama alive past Election Night:
Georgia gubernatorial race
The race for Georgia governor has drawn celebrities and politicians -- including former President Barack Obama, President Trump, Vice President Pence and Oprah Winfrey -- to the state to campaign for their respective candidates.
Democrat Stacey Abrams is neck-and-neck with Republican Brian Kemp, and Libertarian Party candidate Ted Metz could also shake up the race by peeling voters away from both candidates. Not only could the closeness mean the race is decided late, but Georgia requires the leading candidate to pass a 50 percent threshold to avoid a Dec. 4 runoff. Should neither candidate achieve that, it would lead to another month before we know who is Georgia’s next governor.
Another race that could be decided by a run-off is in Mississippi, where two Republicans and two Democrats are vying to fill retired Republican Sen. Thad Cochran’s seat for the remaining two years of his terms.
While Cindy Hyde-Smith, the Republican appointed to the seat in April, enjoys a comfortable lead in the polls, Mississippi law requires the winning candidate to pick up 50 percent to avoid a run-off. Not even Hyde-Smith’s campaign thinks she will hit the 50 percent mark, meaning that a run-off is likely -- something that would draw national attention to the South in the next few weeks, especially if control of the Senate is still at stake.
The closest race in the Senate toss-ups is in Arizona, where Democrat Kyrsten Sinema is challenging Republican Martha McSally.
Due to its geography, Arizona will start counting later. That combined with the appearance that the race is a dead heat could mean we may not have a winner declared by the time the sun comes up on the East Coast.
Wisconsin gubernatorial race
Wisconsin Gov. Scott Walker is locked in a tight re-election battle with Democratic challenger Tony Evers. Fox News Power Rankings has rated the race “lean Democrat” but the contest has been close for months. Former President Obama campaigned in Wisconsin as the Democrats try for the fourth time to deny him the governorship.
With the race so close, it could be a late photo finish that could carry into Wednesday.
California, due to its position on America’s West Coast, frequently calls its races later than the rest of the country. One of those races could be the 48th District, where incumbent Republican Rep. Dana Rohrabacher is likewise in a dead heat with Democratic challenger Harley Rouda.
It’s not impossible for control of the House to come down to just a handful of seats, meaning that delayed calls would keep political leaders on edge into the morning. Rohrabacher's seat is one of five toss-up races in California that could determine which party wins House control.
Fox News’ Jonathan Serrie, Alex Pappas and Andrew O’Reilly contributed to this report.