Because I don't have the ability to configure it. John does, but I do not know what is on his plate right now.
In the meanwhile, how about you and others helping out by making sure that these threads get a keyword of "illegals", "immigration" or "borders"? Then I can find them more easily just by using this and this and this.
The keyword in use by the pingers (gubamyster, madfly, and myself primarily) is Aliens, and I post a button routinely that activates that keyword search.
I realize 'Aliens' is misleading, since the problem we are discussing is actually illegal aliens... but it's shorter and I'm hoping that thinking FReepers realize the difference.