FILE - In this June 23, 2020, file photo voting stations are set up in the South Wing of the Kentucky Exposition Center for…
In this June 23, 2020, file photo voting stations are set up in the South Wing of the Kentucky Exposition Center for voters to cast their ballot in the Kentucky primary in Louisville, Ky.

A week after casting their ballots, voters in the U.S. state of Kentucky are set to learn Tuesday who won the Democratic primary for the U.S. Senate. 

The winner goes on to face Senate Majority Leader Mitch McConnell in the November general election. 

Former Marine fighter pilot Amy McGrath and state lawmaker Charles Booker have traded small leads since election day as local jurisdictions turned in their results from mail-in voting. 

Kentucky received requests for nearly 900,000 such ballots, an unusually high number that came in response to the ongoing coronavirus pandemic.

In this Tuesday, June 23, 2020 file photo, poll workers instruct a voter on where to go to fill out their ballot during the Kentucky primary at the Kentucky Exposition Center in Louisville, Ky.

A high volume of mail-in ballots is also playing a role in Democratic Party primaries for House of Representatives seats in the state of New York, which also held its in-person voting last week. 

Winners have yet to be declared in several key races with major ramifications for the Democrat-led chamber. 

Before counting the mail-in votes, Former middle school principal Jamaal Bowman, who had never run for office before, held a lead of 61% to 36% over Congressman Eliot Engel, the chairman of the House Foreign Affairs Committee.  

Congresswoman Carolyn Maloney, who chairs the House Oversight Committee, held a slight lead over lawyer and activist Suraj Patel before the mail-in ballots were counted in their race. 

The ballots only had to be mailed as of election day, so election officials are still receiving and counting them.