There is the false premise upon which your question/thesis is built.
They won't. They know what their Democrat vote is worth (for now, at least) and the reward is entitlements. Why on earth would anyone in that position actually work and pay taxes?
They are going to b given refugee status that entitle them to endless and maximum freebies and dispersed all around the US.
Some details in this CanadaFreePress article:
http://canadafreepress.com/index.php/article/70143
With all the entitlements and outright gifts from the government they will live much better than they could possibly have lived in the Old Country. Why work your ass off for marginally more, and maybe less?