Foxx takes 15 percent support among Republican voters, to Berry's 14 percent support. Ten percent each prefer State Senate President Pro Tem Phil Berger and Rep. Renee Ellmers. A full 28 percent are still undecided, or would prefer someone else.

Republicans believe Hagan is vulnerable in 2014. They hope to tie her as tightly as possible to President Obama, whose approval rating in the state is underwater: 53 percent of respondents in the new poll say they do not approve of his job performance, while 45 percent approve. That is a net drop of five points since PPP last polled the state, in March.

The PPP poll was conducted from May 17-20 among 500 North Carolina voters and 366 Republican primary voters, and has a margin of error of plus or minus 4.4 percentage points overall, and 5.1 percentage points for the Republican primary.