(CNN) - The battle for Ohio's open Senate seat remains deadlocked, according to a new poll. The Quinnipiac University survey's Wednesday release comes as Vice President Joe Biden heads to Cleveland to lend a helping hand to Lt. Gov. Lee Fisher, the Democratic nominee.
The poll indicates that 42 percent of Ohio voters back Fisher, with 40 percent supporting former Rep. and Bush administration budget director Rob Portman, the GOP nominee. Fisher's two point advantage is basically unchanged from Quinnipiac surveys conducted in March and April and is within the poll's sampling error.
"The Senate race remains far, far from any kind of clear picture, mostly because neither candidate is well known to Ohioans. Even though Fisher has been a figure in Ohio politics for two decades, 54 percent of voters say they don't know enough about him to form an opinion. For Portman, 66 percent can't rate him. With four months until Election Day the Senate race is wide, wide open," says Peter A. Brown, assistant director of the Quinnipiac University Polling Institute.
According to the survey, Fisher is overwhelmingly winning the Democratic vote and Portman the Republican vote, with independents split. Both candidates are fighting to succeed two-term Republican Sen. George Voinovich, who is not running for re-election.
Biden will campaign and headline a fundraiser in Cleveland Wednesday for Fisher, who survived a tough primary contest against Ohio Secretary of State Jennifer Brunner. Fisher beat Brunner by 11 points but had to spend a good amount of his campaign cash in the primaries.
Biden has become the go-to guy in the Obama administration to help out Democratic candidates in this year's midterm elections. In the past week and a half, he's hit the campaign trail for Alexi Giannoulias, the Democratic Senate nominee in Illinois, Dan Seals, the Democratic nominee for the House seat in Illinois 10th congressional district, Sen. Russ Feingold of Wisconsin who's up for re-election this year, and Chris Coons, the Democratic candidate for Senate in Delaware who is hoping to keep the vice president's old seat in party hands.
The poll also indicates that 45 percent approve of the job President Barack Obama's doing in office, with 49 percent saying they disapprove - a breakdown that is basically unchanged from April. By a 53 to 40 percent margin, independent voters disapprove of Obama's performance in the White House.
"Given Ohio's key position in the Electoral College, the White House needs to keep a sharp eye on the president's numbers in the Buckeye State. They aren't awful, but they aren't good either," adds Brown.
The Quinnipiac University poll was conducted June 22-27, with 1,107 registered Ohio voters questioned by telephone. The survey's sampling error is plus or minus three percentage points.
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