The best thing about this is the deterrent factor.
If those outside the country know we won’t do anything about it, in comes the tidal wave.
Knowing it’ll be enforced, helps stop it at the source.
Not to long ago, there was a wave of refugees heading to Australia in boats. When they made it clear they would not be admitted, the boats stopped - imagine that.
The deterrent factor should kick in to higher gear also when boarder detentions/deportations start to increase.