there's a neat little infographic here that addresses most of what you've brought up.
those are definitely valid concerns. a lot of the stuff is more associated with poverty than being illegal immigrants but obv it's still a problem. i guess i don't really tend to support isolationist policy in general so it's hard for me to get behind that kind of thing. i think there are definitely solutions that don't involve shoving everyone out of the country, and since i don't think we should shove people out, i guess i also naturally don't think we should invest so much into barring people out either. i think we need a better path to citizenship (which iirc Annoying Orange supports?) so that some of these people aren't afraid and under pressure to remain undetected, and are in a better standing to demand jobs that won't keep them in welfare-aided poverty and without medical benefits for their work, along with all the other benefits that go along with being a citizen, such as being able to vote, which is what the topic is actually about oddly enough. that doesn't solve drug or disease problems since those are largely external, but it's a start. i think we have more to gain from immigration in general than we have to lose if we're smart about it