Poll: Huckabee's lead continues in Iowa
© Greg Nash

Former Arkansas Gov. Mike Huckabee (R) continues to lead early polling in Iowa for the GOP presidential race in 2016. 

Huckabee, who won the first-in-the-nation GOP caucus in 2008, topped a list of potential 2016 GOP candidates, with 20 percent saying they would most likely vote for him if he decides to run, according to a survey by the Democratically affiliated Public Policy Polling released Thursday. 

A February survey from PPP had Huckabee polling at 17 percent, inside the 5.6 percent margin of error. 

Sen. Ted CruzRafael (Ted) Edward CruzCruz's Dem challenger slams Time piece praising Trump Race for Republican Speaker rare chance to unify party for election 32 male senators back Senate women's calls to change harassment rules MORE (R-Texas) trailed closest behind, with 15 percent. Former Florida Gov. Jeb Bush scored 12 percent and Sen. Rand PaulRandal (Rand) Howard PaulOvernight Defense: Congress poised for busy week on nominations, defense bill | Trump to deliver Naval Academy commencement speech | Trump administration appeals decision to block suspected combatant's transfer Democrats mull audacious play to block Pompeo Overnight Defense: Trump steps up fight with California over guard deployment | Heitkamp is first Dem to back Pompeo for State | Dems question legality of Syria strikes MORE (R-Ky.) took in 10 percent. 

All other candidates scored in single digits: New Jersey Gov. Chris Christie (9 percent), Wisconsin Rep. Paul RyanPaul Davis RyanA warning to Ryan’s successor: The Speakership is no cakewalk Republicans divided over legislation protecting Mueller The Hill's 12:30 Report MORE (8 percent), Wisconsin Gov. Scott Walker (6 percent), Florida Sen. Marco RubioMarco Antonio RubioStudents gather outside White House after walkout to protest gun violence Overnight Energy: Senate confirms Bridenstine as NASA chief | Watchdog probes Pruitt’s use of security detail | Emails shine light on EPA science policy changes Senate confirms Trump’s pick to lead NASA MORE (4 percent) and former Pennsylvania Sen. Rick Santorum (3 percent).

Another 13 percent of Republicans were undecided.

Huckabee has the highest favorable rating among Republicans, at 70 percent. Fourteen percent have an unfavorable view of him.

Christie has the only favorable rating that is underwater. Thirty-six percent of Republicans have a favorable view of him, while 38 percent have an unfavorable view. Another 27 percent were not sure. 

On the Democratic side, 59 percent were most likely to select Hillary Clinton for the Democratic nomination, leading all other candidates by more than 45 points. Vice President Biden garnered 12 percent. 

Clinton leads all Republicans in a potential head-to-head general election match-up. Paul and Huckabee both shrink Clinton's lead to 4 points. 

The poll surveyed 912 registered voters in the state from May 15-19 and has a 3.2 percent margin of error. The margin increases to 5.2 percent and 5.6 percent for Democratic and Republican samples, respectively.