(CNN) - On the eve of Ohio's primary, a new poll indicates that Lt. Gov. Lee Fisher holds a 20-point lead over Secretary of State Jennifer Brunner in the race for their state's Democratic senate nomination.
According to a Quinnipiac University survey released Monday morning, 43 percent of likely Democratic primary voters back Fisher, with 23 percent support Brunner. But nearly a third of the Democratic voters questioned in the poll say they remain undecided and 44 of those who said they are backing one candidate or another indicate they might change their mind by Tuesday's primary.
A Quinnipiac survey released last week indicated Fisher held a 17-point advantage over Brunner.
"Lt. Gov. Fisher started the campaign better known and raised more money to keep him better known and able to get out his message. On the eve of the primary, he is in very strong shape to win," says Peter A. Brown, assistant director of the Quinnipiac University Polling Institute.
The primary winner will face off in November against former Republican Rep. Rob Portman, who also served as budget director in the administration of former President George W. Bush. The race is to succeed retiring Republican Sen. George Voinovich.
The Quinnipiac University poll was conducted April 28-May 2, with 980 likely Democratic primary voters questioned by telephone. The survey's sampling error is plus or minus 3.1 percentage points.