“The Liberals can no longer take the support of Catholics or visible minority voters for granted,” says the study entitled “Anatomy of a Liberal Defeat,” that was presented in May to the Canadian Political Science Association’s annual meeting.

In 2008, for the first time, Catholics were more likely to vote Conservative than Liberal. Many cited the Liberal’s support for same-sex marriage. In 2006, the study shows abortion was a key reason Catholics voted Conservative, even though the Liberals redefined marriage in 2005. In 2004, Catholics also defected to the New Democratic Party over the sponsorship scandal.

Future behaviour may be hard to predict, said the study’s lead author, McGill University political science professor Elisabeth Gidengil, in a Sept. 11 interview. “There has been a huge change,” she said.

The study shows the two key pillars of Liberal support — Catholic and visible minority voters — have crumbled. Visible minority support for the Liberals has dropped 19 points since 2000.

The reasons why Catholics have long identified with the Liberal Party has been “one of the big puzzles” for political scientists, she said. She suspects it has something to do with inheriting both one’s religious identification and one’s partisanship.

“It could be said the sponsorship scandal began to loosen the party ties,” she said. The scandal prompted Catholic voters to start looking around.

While socially conservative Catholics may have helped Tory fortunes, they are not enough to win them a majority government.

Gidengil stressed concerns over the economy and health care remain the chief reasons voters cast a ballot for a candidate.