Sorcha hit the gong with "Can of Worms." Mexican and Central American workers, both legal and illegal, are necessary to pick our fruit and handle much of our vegetable industry. Who shucks the oysters in oyster bars across much of the lower 50? (And do 101 other low-pay tasks). Often Central Americans. Who sews in the sweat shops? Who sweeps the floors and cleans the toilets, etc. etc. In other words, they are necessary for the underbelly of our economy.
In both the USA and Canada, the legal immigrants are those with skills or money and who will not do the nasty jobs.