"The US would be foolish to lose the Dreamers - many would be a gift to Canada but we should be prepared to manage claims before allowing entry."

Quite magnanimous.  Why not take them the way the U.S. did. No vetting, no known skills, an unknown spoken language?
There are almost a million of them. The American liberal media has highlighted 50 of them and every one shown could be class president.
And you want to pick and chose who you will take and pat yourselves on  the shoulder for your virtue.
Couldn't you at least wait until the U.S. determines their status in the congress where its supposed to be decided rather than by an Obama edict?