AMY MCGRATH - CHARLES BOOKER - SIDE BY SIDE 6-25-2020.png

Democrats Amy McGrath and Charles Booker, candidates for Kentucky's U.S. Senate race to oppose Senate Majority Leader Mitch McConnell in the November 2020 election. 

LOUISVILLE, Ky. (WDRB) -- The outcome of the U.S. Senate Democratic primary in Jefferson County may be known sooner than originally expected. 

Jefferson County results from the June 23 primary were expected to be released by 6 p.m. Tuesday, but elections officials now plan to post vote tallies around 10 a.m. CLICK HERE to review the latest election results.

As of 5 p.m. Monday, former Marine fighter pilot Amy McGrath had taken a narrow lead in the Democratic primary for a Kentucky U.S. Senate seat.

With 81% of precincts now reporting, McGrath has just 1,106 more votes than Charles Booker, a freshman state legislator from Louisville, with fewer than 100,000 votes counted. The current count represents only a small portion of overall votes cast, as many absentee ballots, including at least 185,000 from Jefferson County, have not been counted.

Statewide, mail-in ballots and in-person voting results pushed the turnout for the June 23 primary above 1 million.

Totals from in-person voting at the Kentucky Exposition Center were already included, but absentee ballot totals won't be released until Tuesday.

The winner will face Republican incumbent Sen. Mitch McConnell in the November election.

It's not yet known when results from other counties will be released; Secretary of State Michael Adams Tweeted unofficial results from Fleming, Wayne and Floyd on Monday, and from Johnson County on Saturday. 

In those counties, McGrath was leading Booker and Mike Brohier, a farmer who ran as an outsider. McGrath has the support of establishment Democrats, including U.S. Senate Minority Leader Chuck Schumer. 

But Booker has surged in recent weeks, and the race likely hinges on turnout from the state's largest counties -- Jefferson and Fayette. Booker began gaining ground after receiving endorsements from both major Kentucky newspapers, former Kentucky Secretary of State Alison Lundergan Grimes and the members of the liberal wing of the party such as Sen. Bernie Sanders and Rep. Alexandria Ocasio-Cortez.

He also appeared at the racial justice protests downtown. 

This year's election results were delayed because of the number of absentee ballots that were cast. The state allowed widespread mail-in absentee voting because of the coronavirus pandemic. All absentee ballots had to be postmarked by primary election day and received by county clerks' offices by June 27 to be counted. But in-person voting was also allowed, and many Kentuckians voted in person. 

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