Rep. Tom Cotton, R-Ark., will begin his effort to unseat Sen. Mark Pryor, D-Ark., with a slight edge, as a poll shows a majority of Arkansas voters believe Pryor votes with the much-disliked President Obama.

Cotton — who is expected to announce his Senate candidacy at a barbecue in Arkansas today — leads Pryor 43-41 with 16 percent of voters undecided, according to survey from Harper Polling/Conservative Intel.

Pryor is much better known than Cotton — just 22 percent are unsure of how they feel about him, compared to 40 percent who don’t have an opinion on Cotton — but the extra name ID doesn’t necessarily help the Democratic senator: 40 percent of voters have an unfavorable view of him, while just 38 percent have a favorable opinion.

By contrast, Cotton begins with a 34/26 favorable/unfavorable rating. Moreover, 48 percent of Arkansas voters say the state needs a new senator, compared to just 33 percent who believe Pryor deserves reelection. That statistic might be driven by the fact that 61 percent of voters disapprove of President Obama and 53 percent regard Pryor as a vote for his agenda.

“The result is within the poll’s four-point margin of error, and so the two are technically in a statistical tie,”  Conservative Intel’s David Freddoso noted. “But it’s a bad sign for Pryor, a two-term incumbent in the U.S. Senate, that he is polling so poorly against a relatively unknown opponent — 40 percent of Arkansans don’t know enough about Cotton to form an opinion.”

Freddoso is a former editorial page editor for the Washington Examiner.