Elites want more immigration. The common folk want less immigration. But the common folk only notice immigrants as being bad when they are being unproductive, freeloaders, and terrorists. Very few people complain about the Filipino serving them coffee at Tim Hortons for example. But everyone complains about the Syrian Refugees.
Have a good immigration system where the people who come into the country become community members/productive, and stop publicizing the intake of immigrants. This way the immigrants will integrate into Canada, common folk will not notice them as readily, and support for immigration will stay high.
There is a sacrifice that the elites have to give up, and it is their moral exhibitionism. Justin Trudeau and Chrystia Freeland love the photo ops with new refugees coming into Canada. This is one thing that ought to stop if they want to stop reminding the common folk that there are many many immigrants pouring into Canada.
This, I think, is one way to take the air out from the claims of demagogues.