Danny O’Connor’s chances of pulling an upset in Central Ohio’s 12th congressional district just got a little smaller.

The boards of elections in Delaware and Muskingum Counties on Tuesday certified their results from the August 7 special election, and in both counties the lead for Republican Troy Balderson grew slightly.

In Balderson’s native Muskingum County, the Republican got more than twice as many votes as O’Connor.

In Delaware, Balderson increased his lead by 826 votes compared to results when polls closed on Election Night.

The updated tally gives Balderson a lead of 1,781 votes. Five counties, Franklin, Licking, Marion, Morrow and Richland, still need to certify their results. They face a Friday deadline.

When polls closed on Election Night, Balderson had a lead of 1,750 votes. A Franklin County audit the following day shrank that lead to 1,564.

State law triggers an automatic recount if the margin of victory is within a half of a percent.

The two are competing for a GOP-friendly district where Republicans outnumber Democrats by a two-to-one margin. The 12th district has been represented by a Republican for 77 of the past 80 years, but O'Connor made the special election much closer than many experts predicted. It was also seen as the potential start of a "blue wave" for Democrats hoping to win back the House in November.

The winner of the special election fills the seat, previously held by Pat Tiberi, through the end of this year. Balderson and O'Connor face off again in November, with the winner holding the seat for the next two-year term.