Democrats don’t necessarily need retired Lt. Col. Amy McGrath, a former Marine fighter pilot who rose to prominence thanks to a viral campaign ad, to win Kentucky’s 6th Congressional District. It’s possible they could pick up the 24 seats required to flip the House without her.

But on election night, McGrath’s race against Rep. Andy Barr (R) may offer the earliest indication of whether they will, and of how big that majority could be if they do.

Kentucky’s polls close at 6 p.m. EST, meaning McGrath vs. Barr will be one of the first races to end and one of the earliest swing districts to record an outright winner. A victory for McGrath could portend a big night for Democrats. Even a narrow loss in a district like this one may suggest they have enough momentum to regain the majority.

“It’s a real bellwether race, because it’s one of the targets and because it’s going to be one of the first races called,” said Scott Jennings, a Kentucky-based Republican political consultant.