That's wrong.
Plan "B" has long been in place. It's the current de facto immigration hawk "A" plan and a cousin to the Democrat's war on Poverty/racial division "A" plan.
It's called inertia.
Retain the status quo.
The immigration status quo is as valuable to immigration hawks as those two plans above are to Democrats.
Without the problems of illegal immigrants, poverty, and racial divisions, votes would be difficult to get during election times for either side.
So, the "A" plan for immigration hawks is to maintain the issue unchanged.