CiG
Approximately Infinite Universe
Trump's claim that illegal immigration is a threat to national security is potentially true, simply because you don't know who is coming in.
The rest is rather irrelevant. Having a lower crime rate than the legal residents isn't a reason to let them enter illegally. Why add more criminals regardless of the % to the criminal pool already in the country? The entire point of regulating immigration is to make sure the people that enter aren't negative additions to the populace.
And then you have inconvenient facts like this:
http://fusion.net/story/17321/is-rape-the-price-to-pay-for-migrant-women-chasing-the-american-dream/