Wisconsin Gov. Scott Walker is edging out former Florida Gov. Jeb Bush in the early primary state of South Carolina, a Winthrop University poll suggested Wednesday. Both Walker and Bush -- neither of whom has officially declared his candidacy -- are early front-runners for the 2016 Republican nomination for president, and Walker is leading Bush in South Carolina by less than 1 percentage point outside the survey's margin of error, the poll found. No other potential or actual 2016 candidate got above 9 percent in the poll.

Walker leads Bush, 13.6 percent to 12.7 percent, in South Carolina, the third primary state after Iowa and New Hampshire. No other candidate got double digits. U.S. Sen. Ted Cruz, R-Texas, who officially declared his candidacy late last month, was third with 8.1 percent. He was followed by South Carolina Sen. Lindsay Graham at 7.6 percent, Kentucky Sen. Rand Paul at 6.2 percent and New Jersey Gov. Chris Christie at 5 percent. (Paul declared his candidacy April 7.)

Florida Sen. Marco Rubio, who entered the race Monday, was in eighth place at 4 percent. About 25 percent of respondents were undecided.

As the first primary in the South, the South Carolina contest has strong participation by both evangelical Christian voters and tea party sympathizers. Ex-Arkansas Gov. Mike Huckabee, who came in second in South Carolina in 2008 to eventual GOP nominee John McCain, has the most room to grow among these voters, the poll found. Nearly 60 percent of evangelicals said they would consider voting for Huckabee. Meanwhile, native son Graham isn’t faring well with evangelicals, with more than 60 percent telling pollsters they would not consider voting for him if he ran for president.

Huckabee also hasn’t been written off among South Carolinians who approve of the tea party. About 57 percent of such voters said they would consider voting for him. But Cruz fared best among these voters, with nearly 62 percent saying they would consider voting for the Texas senator. Walker, Rubio, ex-Texas Gov. Rick Perry and Paul had similar showings, with all around 55 percent.

The poll of 946 South Carolina residents was conducted April 4-12. It has a margin of error of plus-or-minus 3.2 percentage points.