Romney takes 50 percent support against Obama at 48. The survey of 750 likely voters has a 4 percent margin of error.

It’s the first poll in weeks to show Romney with the lead in Ohio. The previous Rasmussen survey showed the candidates tied at 48, and most other recent polls show Obama with a small lead.

According to the RealClearPolitics average of polls, Obama is at 48.6 percent support in Ohio, over Romney at 46.7.

Ohio is lining up to be a toss-up state with a high likelihood of swinging the election. It's especially important for Romney, who is generally considered to have a narrower path to victory through the Electoral College. No Republican has ever lost Ohio and gone on to win the presidency.

But Obama can scarcely afford to lose Ohio either. Polls suggest Florida and Virginia are both moving toward Romney, and if Obama lost those two states as well as Ohio, he'd have to win nearly all of the other, smaller swing states. 

A range of polls on Ohio with different results has made it difficult to judge who has momentum. A poll from the Democratic-leaning Public Policy Polling released Sunday found Romney trailing Obama in Ohio, 51 percent to 47. 

But a separate poll from the Ohio News Organization released Saturday found the two candidates tied in Ohio.