LITTLE ROCK, Ark. (AP) — Democratic Sen. Mark Pryor is locked in a tight battle against likely Republican nominee Rep. Tom Cotton, with many voters undecided more than a year before the election, according a poll released by the University of Arkansas on Wednesday.

The school’s Arkansas Poll, which is conducted annually to gauge state residents’ opinions about a range of issues, showed that 36 percent of people who said they were very likely to vote next year said they’d back Pryor. Thirty-seven percent said they’d back Cotton. Twenty-seven percent didn’t know or refused to say. The margin of error was plus or minus 3.9 percentage points.