Sen. Mark PryorMark Lunsford 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.) has a six-point lead over Rep. Tom CottonThomas (Tom) Bryant CottonSenate moving ahead with border bill, despite Trump Hillicon Valley: New FTC chief eyes shake up of tech regulation | Lawmakers target Google, Huawei partnership | Microsoft employees voice anger over ICE contract Lawmakers urge Google to drop partnership with Chinese phone maker Huawei MORE (R-Ark.) in a new poll from Pryor's campaign obtained by The Hill.

Pryor leads Cotton among likely voters by 45 percent to 39 percent, in the live-caller poll, conducted for Pryor's campaign by Harstad Strategic Research. A Libertarian Party candidate has 3 percent and a Green Party candidate pulls 2 percent in the poll.

But a nonpartisan poll released shortly after Pryor's from Talk Business and Hendrix College found Cotton leading Pryor by 44 percent to 42 percent. The automated poll with a live-caller cell phone sample is considered one of the better surveys in the state.

Partisan polling should always be taken with a grain of salt, and Arkansas may be the state where Democratic and Republican polling have differed the most this election cycle. Cotton released his own poll in mid-June that found him leading Pryor by 47 percent to 40 percent.

There has been little public polling of the race from nonpartisan live-calling pollsters, but most of what has been out there has found a tight race.

"The election is far from over, but Mark Pryor has to be considered the favorite to win in Arkansas," argues an accompanying polling memo from Pryor pollster Andrew Maxfield.

Pryor's poll also found a close gubernatorial race, with former Rep. Asa Hutchinson (R-Ark.) leading former Rep. Mike Ross (D-Ark.) by 42 percent to 41 percent.

The liver-caller landline and cell phone poll of 807 likely voters was conducted by telephone from July 7-10, 2014 and has a margin of error of plus or minus 3.5 percentage points.

This post was updated at 6:30 p.m.