The latest survey from Rasmussen shows Democratic Sen. Sherrod BrownSherrod BrownOvernight Finance: Dems seek probe of acting SEC chief | Defense hawks say they won't back short-term funding | Senate seen as start point for Trump infrastructure plan | Dems want more money for IRS Senate Dems call for investigation of acting SEC chairman Dems wait for GOP olive branch after ObamaCare debacle MORE and GOP challenger Josh Mandel both earning 48 percent support from likely Ohio voters. Two percent surveyed said they backed another candidate, with 2 still undecided.

Most polls, though, show an edge for Brown in the race. A Columbus Dispatch poll released Sunday showed the incumbent senator with a 51 to 45 advantage. 

An NBC/Wall Street Journal/Marist poll released Saturday also showed Brown with an edge, at 50 to 45 percent support. A poll last week from Gravis Marketing, however, showed Brown only up 1, at 48 to 47, within that survey’s margin of error. 

But with both President Obama GOP nominee Mitt Romney visiting the state this weekend, their efforts to capture the crucial battleground will likely affect turnout and the Ohio Senate outcome. 

Both campaigns have spent heavily in the state and have focused their efforts on boosting early voting in the Buckeye state. Polls have shown that the presidential race in Ohio is close, with a Columbus Dispatch poll Sunday showing Obama with a 2-point lead at 50 to 48, within the poll’s 2.2 percent margin of error.

The survey was conducted on Nov. 1 and has a 4-point margin of error.