Nothing that you've said about more secure borders would be affected directly by a legal guest worker program. We had such a program during WW-II for example. Where our borders insecure then?
we didn't have tons of illegal drugs coming across our borders after WWII.
Nor did we have 4,000 illegals coming across (in AZ alone)per day. I believe the Mexican govt is encouraging their undesirables to come into our country, so they don't have to deal with them.