Actually, what’s going on is that these folks are not refugees, they are economic migrants who may have passed through several safe countries before coming to the US. They get into the US with whatever visa but they are not eligible for refugee status in the US.
What to do. Well, despite all the happy talk about what a welcoming country Canada is, if they go to a regular border crossing, they will not be allowed to enter Canada.
So they get somebody to drive them to the border and then they cross in a remote area. Once they are in Canada, they can make an asylum claim. While their claim is pending, they get the full benefit of the Canadian welfare state.
To claim that they are “fleeing” the US or to try to blame President Trump for these folks is silly. They’re illegally crossing the border because if they try to leave a safe country (the US) at a regular border crossing, they can’t make a refugee claim in Canada or even be admitted into the country.