Amy McGrath, a former Marine fighter pilot, fended off a challenge from an upstart progressive, Charles Booker, ABC News projects, nabbing the Democratic nomination on Tuesday to take on Senate Majority Leader Mitch McConnell in November.

McGrath's victory comes a full week after voters headed to the polls last Tuesday in the hard-fought Senate primary -- a delay brought on by the influx of absentee ballots due to the coronavirus and the tougher-than-expected contest shaped by the national unrest over racial injustice and police brutality.

The race wasn't expected to be tight just one month ago, but the campaign was upended in its closing weeks by the fallout from the deaths of African Americans at the hands of law enforcement, including two in the state of Kentucky since mid-March.

Despite having the backing of national Democrats and a formidable war chest, McGrath found herself in an increasingly competitive battle for the nomination with Booker, 35, the youngest black state lawmaker in Kentucky from the Louisville-area.