If the battle for Halifax was a horse race, one political scientist would put all of his money on New Democrat Megan Leslie.

"I think she is virtually unbeatable," Jeff MacLeod, a political science professor at Mount Saint Vincent University said in a recent interview.

He pointed to the 2011 election when she was faced Liberal candidate Stan Kutcher, a Dalhousie University psychiatrist with an international profile in the field of mental health. Leslie handily won the race, with more than 51 per cent of the vote.

"She was challenged pretty hard in the last election and they didn't put a dent in her," MacLeod said.

This time, the Liberal candidate is urban planner Andy Fillmore, who secured his nomination last November and has been campaigning ever since.

The Conservatives have tapped Irvine Carvery, a former chair of the Halifax Regional School Board who ran for the provincial Progressive Conservatives in Halifax Armdale in 2013. Carvery finished third in that race.

The Greens nominated Thomas Trappenberg, a computer science professor at Dalhousie University.

'I think the Conservatives are out of it'

The Halifax riding is steeped in political history.

Progressive Conservative Leader and former Nova Scotia premier Robert Stanfield was elected three times as the member from Halifax, starting in 1968.

Another former premier, Gerald Regan, held the seat as a Liberal MP. He was elected in 1980 and went on to hold several portfolios in the federal cabinet.

Progressive Conservative Stewart McInnes was elected in 1984 and served as minister of supply and services and minister of public works.

Liberal Mary Clancy won in 1988 and 1993. She later went on to serve as Canadian consul general in Boston.

But it was Alexa McDonough, the former NDP leader, who held the seat for more than a decade until her retirement in 2008. Leslie has kept the riding NDP orange ever since.

MacLeod said for many voters, their choice for candidate will depend on who they think "will oust the government."

"I think [federal Liberal Leader Justin] Trudeau is probably more popular in this area than others," MacLeod said. "I think the Conservatives are out of it. It really comes down to the NDP and the Liberals."

MacLeod predicts the only way Fillmore could topple Leslie is if "Trudeau really skyrockets."

"If it happened, it would be on Trudeau's name — not his."