COLUMBUS -- Republican U.S. Sen. Rob Portman has opened a 17-point lead among Ohio voters, according to a poll released Wednesday by the Quinnipiac University Polling Institute.

Among 497 likely voters, 55 percent sided with Portman, versus 38 percent for his Democratic challenger, former Gov. Ted Strickland.

The results have a margin of error of more than 4 percentage points.

"Anything can happen in politics, but it would take a collapse of historic proportions for Sen. Rob Portman to lose his reelection bid to former Gov. Ted Strickland," Peter A. Brown, assistant director of the poll, said in a statement. "The first-term incumbent is 17 points ahead and the only ones still holding out hope for Strickland are his family members."

Connecticut-based Quinnipiac regularly gauges the opinions of Ohioans and voters in other swing states on candidates and issues.

Strickland has steadily lost ground in Quinnipiac's polls. He was ahead in early polling more than a year ago, but Portman has gained ground since. Last month, Quinnipiac had the race at 51 percent Portman, 40 percent Stricklan

Kovac is the Dix Capital Bureau chief. Email him at or on Twitter at OhioCapitalBlog.