McConnell challenger McGrath endorses Biden

Amy McGrath, a 2020 Democratic challenger for Senate Majority Leader Mitch McConnell's (R-Ky.) seat, on Friday endorsed former Vice President Joe Biden's presidential bid. 

“Honor and integrity are at the heart of everything Marines do. It’s why I believe so strongly that Joe Biden is the president who can return honor and integrity to the Oval Office," McGrath said in a statement released by Biden's campaign. 

"Joe is the Democrat who can bring our country together, restore our reputation abroad, and bring real change to a nation torn apart by partisanship. We need that now more than ever," she continued. 

McGrath, a Marine veteran who came close to flipping a Republican-held House seat in 2018, officially filed to run for Senate late last year.

She raised nearly $11 million in the third quarter last year, but will likely face an uphill challenge in her bid to capture the seat, which the Cook Political Report rates as "likely Republican." 

McGrath's endorsement comes days before the Democratic primary's first nominating contest in Iowa on Monday.

Kentucky's Democratic primary is set to take place on May 19. 

A new NBC News-Wall Street Journal poll released on Friday showed Sen. Bernie Sanders (I-Vt.) leading the crowded Democratic primary pack at 27 percent support, and Biden close behind at 26 percent.