Foxx's advantage was built off her high favorability among "very conservative" voters, who historically have dominated primary polls — especially during off year elections. Of self-described "very conservative" voters, 21 percent prefer Foxx, versus 17 percent for Myrick and 12 percent for McHenry.

McHenry, meanwhile, is most popular among centrist Republican voters, earning 14 percent of that demographic. That narrowly edges out Foxx, at 12 percent, and Myrick, at 10 percent.

Hagan maintains a lead over any hypothetical Republican opponent at this point, leading Foxx 49-39 percent. Myrick polled the best in a head-to-head matchup, with Hagan holding a narrow 45-44 percent showdown against the retiring congresswoman.

Hagan benefits from an approval rating that remains barely in positive territory. Of the voters surveyed, 44 percent approved of the first-term senator, with 43 percent voicing disapproval.

"That close division over her job performance mirrors what we've seen for her pretty much since she took office, and it also mirrors what we saw for Richard BurrRichard Mauze BurrConservatives leery of FBI deal on informant Senate confirms Haspel to head CIA The Hill's Morning Report: Mueller probe hits one-year mark MORE at this time four years ago," said PPP director Tom Jensen in a release. "2010 turned out to be a strong Republican year and he was carried along with the wave. Hagan seems to face a similar situation -- if 2014 is a good year for Dems, she's popular enough that she should be reelected. If 2014 is a bad year for Dems, she may not be strong enough to survive it."