By Phillip M. Bailey | Louisville Courier Journal

Democrat Amy McGrath has entered the 2020 U.S. Senate contest against Republican incumbent Mitch McConnell, which sets up a possible horserace in increasingly conservative Kentucky.

McGrath, a former fighter pilot, ran for Congress last year against U.S. Rep. Andy Barr, R-Ky., but came up short despite the Democratic "blue wave" that gave them a House majority.

McConnell is the most powerful Republican in Congress and has built a war chest that has overwhelmed challengers for more than 30 years. He is fighting to keep control of the Senate as President Donald Trump gears up for his own reelection. 

Here's what to know.

Who is Amy McGrath?

McGrath, 44, is a Marine fighter pilot with 89 combat missions. She is married to Erik Henderson, a former military service member who is lifelong Republican, and they have three children.

After serving more than two decades in the military, McGrath, who hails from Georgetown, Kentucky, soon returned to run for Congress. Her campaign began with an announcement videotaped in front of a fighter jet and wearing her bomber jacket, which went viral.

The story of wanting to be a fighter pilot helped propel McGrath past then-Lexington Mayor Jim Gray, who was the national party's preferred candidate. She beat him by a near-landslide margin in the 2018 primary.

McGrath talked about her military service as much as anything else during that contest, such as how she earned the call sign of "Krusty" as an aviator. She said it was based from the TV show "The Simpsons" and came from the way her curly hair stuck out the sides of her flight suit cap.

"I did not appreciate the name Krusty at first," McGrath tweeted. "In fact, I hated it, which of course sealed the deal for it to become my official call sign. Over the years, I have begun to embrace ‘Krusty' (as I've heard much worse call signs given to others). So there you go."

McConnell's record is on the ballot

National and state Republicans are prepared to defend McConnell at all costs. The importance of having him in control of the Senate, where the GOP holds a 53-47 majority, has come into focus more as Democrats seized the House last November.

McConnell has blocked many of the House Democrats more ambitious liberal proposals, such as making Election Day a federal holiday. He has also vowed to keep the door shut on other plans such as Medicare for all and the Green New Deal that progressive advocates are pushing for in 2020.

"If I'm still the majority leader of the Senate, think of me as the Grim Reaper," McConnell said in April. "None of that stuff is going to pass. None of it."