If Mitt Romney is looking for a vice presidential candidate who can bring him a big state like Ohio, he apparently will be disappointed in the results of a Quinnipiac poll released Thursday that shows adding Ohio Senator Rob Portman to the ticket won't change anything.

CNN:

According to a Quinnipiac University survey released Thursday, the battle for the Buckeye State's 18 electoral votes is basically a tie right now. Forty-five percent of Ohio registered voters questioned in the poll say they are backing President Barack Obama, with 44% saying they support Romney, the former Massachusetts governor and presumptive GOP presidential nominee. Obama's one-point margin over Romney is well within the survey's sampling error.

The poll indicates the general election race remains a dead heat if Portman is chosen for the No. 2 spot on the Republican ticket, with Obama at 45% and Romney at 45%. The former congressman from Ohio, budget director and trade representative under President George W. Bush was elected to the Senate in 2010. His name has come up often lately as someone Romney may seriously be considering as his running mate.

"Adding Sen. Rob Portman to the Romney ticket produces no measurable change, despite speculation about Portman's potential for helping Romney carry the key state of Ohio," said Peter A. Brown, assistant director of the Quinnipiac University Polling institute.

"Republicans have never won the White House without Ohio and in 2004, for instance, George W. Bush won the state and re-election by 2%, so every little change is important," added Brown.

Surprisingly, nearly six in ten Ohio voters say they don't know enough about Portman to form an opinion, with 26% viewing him favorably and 14% having an unfavorable opinion.

According to the poll, 45% of independent voters say they would support a Romney-Portman ticket, with 39% backing the Obama-Vice President Joe Biden ticket.

Of course, no one can know at this point if any numbers would change if Romney went ahead and picked Portman. And in a state that will be as close a race as any in the country, a few thousand converts who choose Romney based on him picking a favorite son may make the difference between winning and losing in November.

Picking Portman would reinforce Romney's image as a technocrat more interested in solving problems than ideology. That alone might swing some more independents his way - reason enough to give the Ohio senator a serious look.