The latest survey from Rasmussen shows Democratic Sen. Sherrod BrownSherrod Campbell BrownOvernight Finance: House passes spending bill with border wall funds | Ryan drops border tax idea | Russia sanctions bill goes to Trump's desk | Dems grill bank regulator picks Dems grill Trump bank regulator nominees Senate Dems launch talkathon ahead of ObamaCare repeal vote 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.