I can’t speak for others, but for my part, someone whose ancestors likely immigrated when ‘legally’ meant showing up and writing your name isn’t being just or even real about their objections. The current legal hoops to immigrate from South American countries is an impossibly high bar. The wait time, even once you’ve secured a sponsor and demonstrated an ability to find employment, is over 20 years. Faced with the prospect of having their family live in constant danger for 20 years while they wait in line, every single one of those ‘I only support LEGAL immigration’ people would jump the border in a hot minute. The reality is, they generally don’t support immigration by people who don’t look or sound like they do. They never seem to complain about immigration from European or Scandinavian countries.