immigration rules only apply to legal immigrants. So stricter immigration rules is more of a "screw you got mine" kind of thing, illegal immigrants would only be affected by border enforcement and job availability once they got in (which is crazily easy in the USA vs. a country like Canada).
I believe now there are rules on when undocumented immigrants are allowed to apply for amnesty: when the number of illegal immigrants encountered at the border are less than 1500 / day for a week. so now the definition of illegal is directly linked to how many do the activity on a weekly basis.
> immigration rules only apply to legal immigrants.
No, this is clearly false. Rules apply to illegal immigrants too - those who just crossed the border without approval or prior paperwork. Those rules are rather lax and are not enforced as can be seen in the current administration and "sanctuary" states - who simply ignore the rules.
It is sad, because the rules that would really stop illegal immigration, heavy penalties on people who employ them (like Mitt Romney and Donald Trump) are heavily opposed by Republicans. This basically stops the problem completely in Canada, since even if you show up, you can't get any work/money.
I get the feeling that no one is really serious about stopping this problem, since even the rules they propose are obviously ineffective (and probably meant to be).
Funny, the rules that would stop illegal immigration aren't enforced (sever punishment for those providing the job that are encouraging it), but the laws that create a perpetual underclass/powerless class are enforced just enough to keep that class in check (but not enforced enough to prevent the existence of a major source of exploitable labour).
