This story has been updated.

Illinois Congresswoman Tammy Duckworth (D) announced Monday that she will challenge vulnerable GOP incumbent Sen. Mark Kirk in 2016, giving Democrats a top Democratic recruit in the potentially competitive race that could determine control of the Senate.

Duckworth, a wounded Iraq war veteran, has been widely expected to enter the race. Duckworth formally launched her campaign Monday with a video introducing herself as an advocate for the middle class, a recent mom and a combat veteran.

"When I was in high school my dad lost his job at 55 and struggled with unemployment. The bottom fell out for us. For a time, food stamps kept my brother and me from going hungry," she says in the video. "Graduating from college was a challenge but I made it with the help of loans, Pell Grants and lots of waitressing."

In the video, Duckworth describes the tragic attack that left her a double-amputee while she was serving in Iraq.

"The only reason I made it home was because of the heroism of my courageous buddies who risked their lives to save mine," she said. "I view my time now as a bonus. And that has allowed me to speak up without fear."

The Illinois Senate race promises to be one of the most competitive in the country. Democrats see the seat as a top pick-up opportunity in their effort to take back control of the Senate, in part because the presidential election is expected to increase Democratic turnout.

Democrats will need to gain control of four seats to win back control of the upper chamber. The race will likely receive an immense amount of attention from outside groups on both sides of the aisle.

The National Republican Senatorial Committee wasted no time hitting Duckworth, painting her as a partisan member of the Democratic rank and file.

“Congresswoman Duckworth is a partisan politician who got her start in politics as a result of Rod Blagojevich’s political maneuvers," NRSC Spokeswoman Andrea Bozek said in a statement. "Unlike Congresswoman Duckworth, who has put her extreme policies in Washington before Illinois families by voting with Nancy Pelosi 92% of the time, Mark Kirk has been an independent voice.”

The congresswoman is just one of several potential candidates on the left. That list also includes Democratic Reps. Bill Foster and Robin Kelly.

Democratic Rep. Cheri Bustos, who was considered a potential candidate, on Monday indicated that she will likely not pursue the nomination for the Senate seat now that Duckworth is in the race.

“If you look at Tammy’s record of fighting for American manufacturing, for working men and women, and for our veterans, she clearly has the priorities we need in our next U.S. Senator," said Bustos in a statement. “I can’t see jumping into a race at this time when we already have such a strong fighter for working men and women and veterans."

She added that she would not yet make a formal endorsement in the race, citing a "deep bench" of potential candidates in Illinois.

On the Republican side, Former GOP Rep. Joe Walsh told reporters earlier this month that he is considering a primary challenge to Kirk.

Duckworth was first elected to the House in 2012 when she unseated Walsh.

Sean Sullivan contributed to this story.