I can sure as Hell tell you where they aren't, and that isn't where Leger and CROP put them, nearly or actually breaching 20%.
Both of these pollsters, who poll only Quebec, aren't following any other trends seen in any other Canadian pollster, so immediately throw the result into doubt. No matter what you hear, the NDP are not at 20% in Quebec, not by any standards I know of.
So where the heck are the NDP really? We really don't know, because when we get conflicting results from pollsters, there is usually a reason. Think about it this way: no pan-Canadian pollsters have shown the NDP above 15% of the vote in their polls, yet the two Quebec-based pollsters are showing almost the same results. When you eliminate random chance and other variables, then the logical conclusion is that the split between pan-Canadian and Quebec-only pollsters is the main factor, and something they do differently is the cause.
There are several options, however the main one I can think of would be how the two pollsters weigh their results, because obviously when you're polling all of Canada, and when you're polling voters of a specific region, you will weigh your results differently. That's why the idea of Leger or CROP being more accurate is false - we don't know how they weigh those results, so therefore we can't say that just because they focus on a specific area, they're more accurate.
So depending on how Leger and CROP weigh their results, based on whatever trends they perceive the electorate to be moving in Quebec, they can give very different results as compared to the pan-Canadian pollsters. However, the question remains how much they have to have weighed these results in order for them to get results so starkly different from other pollsters. Not only that, it simply doesn't seem right; this would be a definite NDP surge in the polls, but we have no reason for it. Layton hasn't done anything spectacular lately, neither has Mulcair and the other people involved there. What explains the surge? Nothing. And in the polling world, there is no such thing as an unexplainable surge.
Furthermore, consider that it seems the NDP results in those two polls seem to come majorly at the expense of the Bloc Quebecois, which instead of hovering around 40% as they do in pan-Canadian polls, they're waffling around 35% in Leger and CROP. Given that a lot of Bloc support is social democratic, and given the provincial drift of socialists from the Parti Quebecois (PQ) to the smaller Quebecois Solidaire (QS), is it possible that Leger and CROP are weighing their results in such a way that they siphon left-wing votes from the Bloc to the NDP, thereby skewing the results differently from the others?
This is my guess. Because there must be something to explain it - a surge as large as what the NDP are getting from Leger and CROP simply doesn't go by unnoticed by everyone else. Which means that those two pollsters either have their weights wrong, or the pan-Canadian pollsters do. However, I discount the latter because frankly, I haven't seen anything but love for the Bloc in Quebec. And Mulcair's presence isn't enough to explain anything, given that he was there in 2008 and the NDP saw a stable increase from 2006, in line with what pollsters predicted and indeed making sense with their usual trendline in the province (which you can see here). Jumping from 12% to 19% falls outside of this trendline, and far into new territory.
But these are just my guesses. What do the rest of you think? Are the NDP really flying this high in Quebec, or are these pollsters tweaking their results just a tad too much?