In a three-minute video released Tuesday, McGrath said McConnell "made Washington little by little, something we all despise."
"I fight for the Senate because it should not be so," added McGrath.
McGrath's candidacy marks a significant recruitment coup for Democrats. She proved to be an unlikely fundraiser in her congressional race, earning millions of dollars after her campaign released a biographical video that became viral and became a democratic celebrity.
McGrath was not enough to defeat Barr, who won around 3 points in the 2018 election, despite McGrath spending nearly $ 3 million more.
In the race against McConnell, McGrath seems ready to run as a moderator trying to overcome the partisan jam in Washington. In an interview on MSNBC's Morning Joe Tuesday, McGrath said she had followed the Democratic presidential debate and fears that many candidates are too far-flung on issues such as health care.
McGrath, however, will have her work cut out for her. President Donald Trump won Kentucky in 201
Meanwhile, McConnell has proven to be a smart and ruthless opponent. In 2014 he defeated the much-vaunted opponent, the Democrat Alison Lundergan Grimes, with 15 points.
McGrath admitted to "Morning Joe" that McConnell was "impressive" after more than three decades in the Senate. "This is a different breed," she added.
"The things Kentucky's voted for Trump are not being done," McGrath said. "He is unable to do it because of Mitch McConnell."
McGrath brings a compelling biography as the first Marine woman to fly an F-18 fighter in combat. In the video announcing her bid for the Senate, McGrath recalled writing a letter to McConnell as a thirteen-year-old girl, asking him to change the law that women would receive from such missions at the time had ruled out.
"He never wrote back," McGrath recalled.