But there's encouraging signs for Akin. The congressman leads Brunner by two points among voters who say they are "very excited" about voting in the primary, which customarily sees low turnout, and Akin actually leads Brunner 33-30 percent among the "very conservative" voters most likely to show up at the polls. When the poll drops voters who say they're "not that excited" to vote, Brunner's lead shrinks to just 2 percentage points.

Akin also leads narrowly among seniors, and carries a nearly identical favorability rating to Brunner. Plus, the momentum seems to be at the lawmaker's back.

"It's been more than two months since PPP last polled this race but compared to a Mason Dixon poll a week ago Akin's up 13 points while Brunner's gained only two points and Steelman's actually dropped by a couple," wrote PPP's Tom Jensen. "If that trend continues right on through election day Akin might be able to pull out a narrow victory."

Interestingly, Palin's endorsement doesn't seem to have done much to boost Steelman. Among Tea Party voters, Brunner leads the former gubernatorial candidates 35-33 percent, with Akin pulling 28 percent. And Steelman has the worst favorability numbers of the group, posting a mere 6 point net favorability rating among likely Republican primary voters.