First of I don't believe in borders.
But that aside, in my humble opinion the discussion is not about the "open border" but lies deeper and is about the "open wallet", and before that how money gets into that wallet...................I think;)

edit; Don't mind the typical reply of the communist under this reply; he and his government have extorted me for years to get the welfare and warfare "presents" (creating a lot of problems) and still it's not enough, they need to extort and threaten me some more to solve the problems they've created by creating more expensive and freedom stifling problems (they call solutions.) Communists never learn, they live like scared little slaves begging government on their knees to solve their problems and fears.......And in the process killing the ones they extorted, threatened and forced for years, that is the endgame of every communist...they are a death cult.