Ryan now Clinton's strongest rival in Ohio
© Greg Nash

Among Ohio voters, Rep. Paul RyanPaul RyanBorder-adjustment tax proposal at death’s door Overnight Healthcare: CBO fallout | GOP senators distance themselves from House bill | Trump budget chief blasts score | Schumer says House bill belongs 'in the trash' Five takeaways from the CBO healthcare score MORE (R-Wis.) fares the best against Hillary ClintonHillary Rodham Clinton5 things to watch in Montana’s special election Hannity on attempted advertiser boycott: 'Nobody tells me what to say on my show' Overnight Cybersecurity: Bad Russian intel may have swayed Comey's handling of Clinton probe | Apple sees spike in data requests | More subpoenas for Flynn | DOJ's plan for data warrants MORE in a potential 2016 match-up, according to a new poll. 

Clinton continues to dominate the field of potential Republican candidates in the battleground state, according to a Quinnipiac poll released Thursday. 

But Ryan, the former GOP vice presidential candidate, trails Clinton by 9 percent, while all other potential candidates lag by double digits. 

In a head-to-head matchup, 49 percent of voters would cast their ballot for Clinton, while 40 percent would choose Ryan. 

Ryan has become Clinton’s strongest opponent in the state since the George Washington Bridge scandal engulfed New Jersey Gov. Chris Christie’s (R) administration. 

Even so, Clinton has extended her lead on nearly every GOP candidate since Quinnipiac lasted tested the question in November. Ryan trailed Clinton by 8 points in November.  

Shortly after his reelection victory, Christie trailed Clinton by a single point in the state. Today, he trails by 13 percent. In a match-up, 49 percent would vote for Clinton, while 36 percent would choose Christie. 

Ohio Gov. John Kasich (R) trails Clinton by 12 percent. Fifty-one percent would vote for Clinton, while 39 percent would choose Kasich. 

Other potential GOP candidates, including Florida Gov. Jeb Bush and Sens. Marco Rubio (Fla.) and Rand Paul (Ky.), trail Clinton by between 14-15 points. 

Sen. Ted Cruz (Texas) polls the worst, trailing Clinton by 17 percentage points. 

President Obama’s approval rating has improved since hitting an all-time low of 34 percent in November amid the botched rollout of the healthcare law.  

Forty percent of Ohio voters approve of the president, while 55 percent disapprove of him. 

Eighty percent of Democrats approve of the president, while only 30 percent of independents feel the same. His approval rating with Republicans stands at 8 percent. 

The poll surveyed 1,370 registered voters earlier this month and contains a 2.7-percent margin of error.