Ohio's 18 electoral votes are considered pivotal to both campaigns; no Republican has ever won the White House without winning Ohio.

As in other states, a significant gender gap is apparent in the Ohio electorate. Obama leads Mitt Romney 46 to 43 percent among women, while Romney leads 50 to 41 percent among men.

The Democrats are the favored choice of the 18- to 29-year-old demographic but trail substantially among voters 30-49 percent. Those over 50 favor the Republican ticket by a single percentage point.

The poll also found the slimmest of leads for Republican U.S. Senate candidate Josh Mandel, who holds a lead of just fractions of 1 percent over incumbent Sen. Sherrod BrownSherrod BrownFive things to know about Trump's steel order Trump administration investigating effect of steel imports on US Mexico: Recent deportations 'a violation' of US immigration rules MORE (D-Ohio). The virtual tie matches Brown's best showing in polls to date; Mandel has never led by more than a percentage point in a public head-to-head poll.