I don't think you have the first clue about what the existing laws, effective Administrative rulings, or controlling court precedents are.
Arne, what part of "illegal alien" do you not understand? All we need to do is enforce the existing laws. Make it painful for employers to hire illegals - instead, the INS hardly bothers to perform workplace checks any more. Significantly reduce the flow on the border (you are correct that it can never be stopped completely - but that is no excuse for not making much of an effort).
There is no legislative agenda needed - however, the Administration, Congress and the business community winks and nods at the problem. You might think that's a good thing, and there is a fair debate to be had as to what is a realistic immigration policy. However, that does not change the fact that your opponents do not have to propose ANY legislative agenda, as the laws are already in place to combat this issue. They are simply not being enforced.