Sen. Mark PryorMark PryorMedicaid rollback looms for GOP senators in 2020 Cotton pitches anti-Democrat message to SC delegation Ex-Sen. Kay Hagan joins lobby firm MORE (D-Ark.) and Rep. Tom CottonTom CottonCotton: I hope we go back to health care next year Sunday shows preview: GOP gears up for Senate tax reform push A simple way to make America even greater is fixing our patent system MORE (R-Ark.) are in a tied Senate race, according to a new survey from Democratic firm Public Policy Polling.

Pryor and Cotton each pull 44 percent of the vote in the poll, obtained by The Hill.

Pryor is widely viewed as the most vulnerable senator up for reelection in 2014, and the poll is the latest to show a tight race in the heavily Republican state. A poll from a GOP group backing Cotton released last week found him with a lead, while other polling has shown a close race.

The numbers aren't a great sign for Pryor, however, as undecided voters tend to break toward the lesser-known candidate. Pryor led Cotton by 44 percent to 41 percent when PPP last surveyed the state in October.

The race has already heated up: Both candidates are already on the air with television ads as are a number of outside groups.

The automated poll of 1,004 Arkansas voters was conducted from Dec. 13-15.