Your examples are proving how really ignorant you are!
Again the shooter husband was born here and she came here on a visa. The soldier came here and was allowed to join the military and came here on a visa. The bombers again visa. 9/11 again visa...
So tell me when was the last time they came across the border illegally?
Oh, that's right it has been NEVER!
But why leave them an opening if you can close it?
It's like leaving your doors unlocked during a crime wave.
Again, show me where any terrorist has come across the Mexican border illegally or even the Canadian Border illegally, and committed a terrorist attack on our soil that was in the name of ISIL or Al-Qaeda, and my bet you can't.
What is amazing is all the Islamic attacks have been done by homegrown or those that came here on visas, but hey let pretend they were all illegal.
The terrorist don't need to come here illegally when they can come here on a visa or recruit some pathetic loser that was born here to do their attacks!