Loss of support: They lost a lot of support in Quebec because they aren't against banning wearing a Niqab when you take a citizenship oath and shit cause French people don't like Muslim people and that's where they stole a lot of seats last year.
A lot of last time NDP voters were just fed up Liberals voters, but once they got on good footing again they jumped back on board.
Our voting system is severely flawed so to get out one of the worst PM of the last 50 years we had to strategically vote for whichever party had the best chance to oust Harper. As it got closer to election time it showed a lot of ridings could go either conservative or liberals so a lot of NDP voters even switched parties. We do a first past the post system which if you don't know what it is look it up cause I don't feel like typing it all out.
Mulcair is a terrible leader and has nothing really going for him. I think this election would've been different if we had a different leader. I heard he was almost a conservative before joining the party but I haven't looked into that, but I do know he did praise Thatcher at one point (a little Brit name dropping to keep you interested). Really last election was fought on the back of one of the great party leaders of the last 50 years, Jack Layton. Everyone really liked him regardless of political affiliation.
Also, polls just kind of lie here. Maybe lie isn't the best word, but I guesss really inaccurate. No one predicted the last two majorities at all. They said it should've been a tight race for a minority government.