Hillary ClintonHillary Diane Rodham ClintonClinton backs Georgia governor hopeful on eve of primary Pressure rising on GOP after Trump–DOJ fight’s latest turn Press: Why Trump should thank FBI MORE (D) leads Chris Christie (R) by a narrow margin in a hypothetical 2016 presidential match-up, according to a Quinnipiac University poll released Friday.

The former secretary of State topped the New Jersey governor 46 percent to 40 percent in the poll.

Both potential candidates registered strong favorability ratings. Clinton has a 55 percent favorability rating, while 38 percent of voters had an unfavorable view. 

Christie had 45 percent favorable rating and 18 percent unfavorable. Christie is viewed favorably by a plurality of Democrats by a margin of 41 percent to 19 percent, according to the poll.

“Former Secretary of State Hillary Clinton remains the front-runner for 2016 if she chooses to run," Peter A. Brown, assistant director of the Quinnipiac University Polling Institute, said in a statement. 

"But New Jersey Gov. Christopher Christie's favorability numbers are impressive and if he can win over a solid share of those who do not yet have an opinion about him, he could be a very formidable candidate in 2016. Candidates with more than 2-1 favorability ratios don't grow on trees."

The second tier of candidates from both parties would trail Christie and Clinton by double-digits. Christie leads Vice President Biden (D) 46 percent to 35 percent in a head-to-head match-up, while Clinton tops Sen. Rand PaulRandal (Rand) Howard PaulSarah Sanders: ‘Democrats are losing their war against women in the Trump administration’ Kentucky Dems look to vault themselves in deep-red district Overnight Defense: Senate confirms Haspel as CIA chief | Trump offers Kim 'protections' if he gives up nukes | Dem amendments target Trump military parade MORE (R-Ky.) 50 percent to 38 percent.

None of the potential candidates have publicly committed to a 2016 run. However, Ready for Hillary, a super-PAC pushing the former New York senator to run, is loaded with former Obama campaign activists.

The Quinnipiac poll of 2,014 registered voters was conducted between June 28 and July 8 and has a 2.2-percentage-point margin of error.