1) Ultimately, it comes down to Math. The Math is not insurmountable. The House of Commons has 338 seats. Depending on the outcome of post-election machinations in a minority government, the NDP only needs to win slightly over a third of those seats assuming the seat counts for the Liberals and the Conservatives are roughly similar. Meaning the NDP could win with as few as 120-130 seats assuming around 100-110 seats each for the Liberals and Conservatives and a small handful of seats for other parties (Green, BQ). It might ultimately take more than one election to leapfrog the other parties' seat counts due to a) incumbency, b) establishing a level of comfort and familiarity with the electorate and c) establishing a beachhead of support in certain urban and suburban ridings that are not used to voting NDP but it's possible to grow from an existing base of 44 seats up to 120-130 seats in 1 or 2 election cycles with the right message and strategy. The reason I think it might take more than 1 election cycle is because many voters take time to break out of existing habits (eg. not ever previously voting for the NDP federally).
2) A growing proportion of Canadians are visible minorities. Jagmeet will speak to them. The proportion of these non-white Canadians is about one quarter. The NDP does not traditionally do very well with visible minorities. If visible minorities make up 25% of the electorate and whites make up 75%, the NDP may get around 5% of its total vote share from minorities (5/25) and the rest from whites (10-15/75). Jagmeet can increase the minority share from 5/25 to over 10/25 due to his popularity with South Asians, Muslims and others. If Jagmeet can get 12/25 among nonwhites and maintain 15/75 among whites, that puts the NDP at a very healthy 27% of the popular vote, just a few points shy of what they would need to win. This is doable. By doing better with visible minorities, Jagmeet can increase the NDP's currently miserable seat count in Ontario (8 seats) by a considerable amount (30+).
3) The Trump Factor is likely to be very helpful to Jagmeet. Most Canadians find Donald Trump extremely distasteful. Justin Trudeau has done a good job of branding himself as the anti-Trump but no one is going to symbolize anti-Trump more than a bearded man with a turban. Canadians don't have the luxury of voting out Trump in 2020 but they do have the option of sending an emphatically anti-Trump/anti-Racism message in 2019 by voting for Jagmeet.
4) Quebec politics are re-aligning. So you might ask, what about Quebec? Aren't they racist or at the least, skeptical of Jagmeet's supposedly overt religiosity? Maybe but as Chantal Hébert noted in her column yesterday, Quebec politics are re-aligning from a federalist-sovereigntist axis to a left-right axis. Considering that the Bloc Québécois is fading away due to this shift in Quebec politics, the new left-right axis will benefit the NDP in the long-term. Quebec's politics already lean-leftward compared to the rest of the country and with a compelling enough platform, Jagmeet can make a case to have Quebecers vote for his proposals rather than his race or religion. Ultimately, the Liberals have not fundamentally altered the status quo in Canada in a major way. The NDP can do that with free university tuition, a national childcare program, dental care, pharmacare among other proposals. This can be compelling stuff to socially-democratic minded Quebecers if Jagmeet puts forward an ambitious (albeit potentially unfeasible) agenda. Many voters shift between the NDP and the Liberals. Having an aggressively left wing platform will likely do a great deal to pry left wing voters away from the Liberals and into the hands of the NDP, particularly in Quebec.
5) Jagmeet will catch people's attention including the media's. Jagmeet is going to stand out. He will have almost universal name recognition by the time of the next election. Tom Mulcair couldn't say the same for himself. Name ID is incredibly important since most voters tune out politics a majority of the time but if Jagmeet can make himself recognizable and attractive to low-information voters, he can unlock a huge chunk of the electorate for the NDP.
6) The NDP has a good bench of talent. Jagmeet has a lot of good options to choose from when assembling his shadow cabinet. These include his three opponents in the leadership race (Niki Ashton and Guy Caron could make a good deputy leader combination) among several other impressive NDP MPs. There are also several dozen recently defeated MPs who can run again for the NDP in 2019.
For the above reasons I think Jagmeet has a better shot than many realize at becoming Prime Minister. Although it all starts with him becoming leader next month...
