President Barack Obama leads Mitt Romney by 5 percentage points in Ohio, a new poll released Sunday has found.

The poll, commissioned by Cleveland's The Plain Dealer and other major newspapers in the state, shows Obama leading Romney 51 percent to 46 percent.

More people said they trust Obama to improve Ohio's economy.

“Clearly, how Ohioans view the two candidates in terms of their ability to improve Ohio's economy over the next four years will go a long way in determining who wins Ohio's 18 electoral votes,” said Eric Rademacher, co-director of the University of Cincinnati's Institute for Policy Research, which conducted the survey.

The survey touched slightly on marriage equality, asking respondents if where the candidates stood on the issue would affect their vote. Fifty percent answered “no.”

Romney increased his opposition to gay rights as he courted social conservatives in his bid to become the GOP nominee, and attempted to stave off accusations from his rivals that he somehow supported or enabled the legalization of gay marriage while serving as governor of Massachusetts. For example, he said late last year that he could only support a limited partnership which includes “such things as hospital visitation rights and similar things” for gay and lesbian couples.

On the other hand, Obama is the first sitting president to endorse marriage rights for gay couples. His May announcement led to a historic plank in support of such unions in the 2012 Democratic Party Platform.

Opponents have mounted a campaign around the issue in Ohio and other tossup states.

A billboard erected in Cleveland's Midtown Corridor states, “Obama supports gay marriage and abortion. Do you?” and calls on voters to “Vote Republican.” The nascent super-PAC Republican Union PAC spent $950,000 to erect the billboards in five key states: Florida, Michigan, Ohio, Pennsylvania and Virginia.

Pollster interviewed 861 likely voters by telephone between September 13 and 18.

(Related: Mitt Romney is a homophobe, gay activist Dan Savage says.)