All any law needs to say, is that anyone caught crossing between Ports of Entry are immediately arrested and given a 1 year prison sentence. Then deported to Ecuador in the middle of the night.
That'd be part one.
Part two would say that anyone claiming asylum must do so from either Mexico or Canada AND show multiple forms of proof supporting their asylum claim.
If they don't pass, they too get deported to Ecuador in the middle of the night.
Part three, the government is prohibited from allowing any entry once the gov does not have adequate manpower to keep track of those already here.
Same applies to the number of Judges hearing cases. Once the backlog reaches one Month, all new claims are halted.
If it still is a problem, line the border with the military.
That's all any new border security law needs to say.