Third mistake? Mulcair did what Andrea Horwath and Olivia Chow did. He moved to the right, big time. On deficits, on defence, on doing just about anything in government: the New Democratic leader didn't sound like a New Democrat, at all.
In his mad dash to get to the centre, he left behind his bewildered core vote - and he left everyone else bewildered, too. Election time, as Horwath and Chow discovered the hard way, is no time to toss out everything everyone ever believed about you. Among other things, it's confusing.
Why are the NDP bleeding support? They've strayed from where they were in the quest to solidify centrists votes; their base feels uprooted and everyone else sees the NDP as a policy tumble weed.
Why have the Harper Conservatives been able to grow? For starters, they have never abandoned their base, which means their floor has never lowered. Their roots are deep and the party ain't shifting ground.
More than a couple positions that keep their base rock-solid, however, are anathema to voters on the other end of the spectrum. You can't be all things to all people, but you can't win majorities off of your base alone.
So Team Harper has perfected the art of the wedge-issue, essentially side-stepping substantial policy challenges and appealing to people's baser instincts. You can be a left-leaning, pro-separation Quebecer but hey, if the niqab/scary Muslim things makes you skittish, you might just base your vote on that alone.
That's what modern politics is about, after all - adding just the right pieces to your narrative to expand your coalition into the small percent of non-locked voters to form a majority.
While Team Harper is mighty effective at this, the consequence of their wedge-issue mentality is an increasingly divided, embittered and angry country. Anger is better than confusion for gaining support - it's so clear, so motivational! - but it's a dangerous state to keep a nation in for long periods of time.
If not anger and wedge-issues, though, how do you add enough support to your coalition to win? More to the point - how do you not push the short-term effective, long-term destabilizing anger-button when the other guys are doing so and clearly benefiting?
There is a massive difference between winning power and nation-building and increasingly, it's hard for Canada's political parties to play that role - a role they were never intended to play, anyway.
Perhaps the question needs to change. Instead of parties asking what does it take to win, we should all be asking where do we go from here?