CALGARY - A right-wing political party that once operated on the fringe of Alberta politics appears to be gaining ground.

Earlier this week, the Wildrose Alliance shocked many observers by winning a provincial byelection in Calgary. Then on Wednesday night, an overflow crowd of more than 400 people turned out to a Calgary hotel ballroom for a debate among candidates for the party's leadership.

They are Jeff Willerton, an author and businessman; Mark Dyrholm, a Calgary chiropractor; and Danielle Smith, former head of the Alberta wing of the Canadian Federation of Independent Business.

Paul Hinman, who took the Calgary-Glenmore riding away from the Tories, who had held it for 40 years, is the interim leader of the Wildrose Alliance but is not seeking the job in the October vote.

There was considerable excitement about the party's prospects at Wednesday's debate.

"There has been an increased level of momentum and excitement and enthusiasm," said party spokesman Geff Callaway. "The phones are ringing off the hook and the emails are rolling in."

The party also says it is selling thousands of new memberships in the wake of Hinman's byelection victory.

"We have to hire more staff because we can't process the phone calls of people wanting memberships, and the donations that are coming in," Hinman said Wednesday.

"The floodgates got opened."

Political scientist David Taras said there is little doubt the Calgary-Glenmore victory was "explosive" for the party.

He said once the party picks a leader, it will need to capitalize on those voters who are abandoning the Conservatives under Premier Ed Stelmach.

"We don't really know what this party will be, but there is this anger looking for a place," he said. "There is thunder on the right, and the Tories are very nervous."

The leadership vote will be held Oct. 17.