As Milton Friedman intoned, you CANNOT have an open border and a welfare state. We had no welfare state 100 years ago when we last had massive LEGAL immigration.
The secret to America's prior success as a nation formed by immigrants was INSISTING that they learn English and embrace become Americans...Hispanics do not care to.
I am ALL FOR attaching Green cards to those advanced degrees we grant to foreigners.
We MUST stress what emigrants can do for AMERICA, NOT what THEY might want.
America is like a beautiful woman agreeing to have sex-- she MUST BE selective.