It's been a nail-biting race for the congressional District 15 runoff election between Democrats Ruben Ramirez and Michelle Vallejo.

More than 24 hours after polls closed, it’s unclear who will face off against Republican Monica De La Cruz in November.

Both Ramirez and Vallejo have sent statements saying it’s too soon to consider a virtual winner.

For now, election departments in counties within District 15 have to count mail-in ballots, votes from abroad and provisional ballots.

“In 15, without question, we’re going to have to wait until at least next week to have a good idea about who the winner is,” said Mark Jones, a political science professor at Rice University.

According to an analysis from the University of Virginia, voters in Hidalgo County are leaning more towards Republican candidates.

Jones says if a progressive candidate such as Michelle Vallejo ends up winning the runoff, then that can actually favor Republican candidate Monica De La Cruz and she might be victorious in the November election.