A recent debate saw candidates try to strike a balance of respect for Flaherty's memory, while taking shots at his party. The riding was vacated when the long-serving MP and finance minister died in April.
"Whatever you think of the Conservatives, they have become a tired and hard government," NDP candidate Trish McAuliffe told the crowd.
For Tory candidate and former Whitby mayor Pat Perkins, Flaherty's ghost is a talisman.
"He gave this area the best representation we've ever had," Perkins said. "His participation and partnerships with me at the municipal level was a great boon to this area."
Pundits say the Conservatives need to hang on to the riding to curb the momentum Justin Trudeau has built over the last year — posing a potential threat as Canada edges toward a federal election in 2015.
The leaders of the federal parties seem acutely aware of the riding's importance as each of them has recently visited Whitby-Oshawa.
Prime Minister Stephen Harper came by to plug the Conservative's child-care plan, which was rebutted during a visit by Trudeau. A visit from the NDP's Tom Mulcair followed.