The poll also shows Rep. Tom Cotton (R-Ark.) leading Pryor in a hypothetical matchup by 43 to 35 percent. Cotton, a Tea Party favorite well-liked by the groups, has refused to discuss whether he's considering running for the seat.
The Democratic Senatorial Campaign Committee pushed back on the poll.
"The people of Arkansas elected Tom Cotton five minutes ago," said DSCC spokesman Matt Canter. "If he already deems himself worthy of a promotion, then he is in for a lot of disappointment. The fact is that this sham poll is brought to you by the Joe Miller, Richard Mourdock, Todd Akin wing of the Republican party. Reince Priebus tried to excommunicate these guys yesterday."
Both polls were of 600 registered voters and had margins of error of plus or minus 4 percentage points. The most recent poll was conducted from March 16-17, while the first poll was from Jan. 27-28.
This post was updated at 10:15 a.m.