Sorry for not answering, Minnesotans are sleepy
I think there is still a misunderstanding about what an open border means. Right now a pedophile could come over, do their thing, and go back no problem. Customs would be the same, taking vacations would have the same security and you would still need a passport. An open border is just a term meaning that you can become a citizen without having to wait in line. It means that there is no maximum number of people that can become citizens. There would still be background checks to make sure that they aren't active drug dealers, on probation etc. It would be just as easy for someone to "run back and forth" with an open border as it would be now. The only difference is that it doesn't take up to 20 years to be granted citizenship, but rather a few months or even a few weeks.
Anyway I guess people here don't understand progressive ideas so maybe we should get back on topic.