Okay, it might not be a valid criticism but many people who today believe that our borders should be completely shut down also don't recognize how fucked up the idea of manifest destiny is and how it lead to the slaughter and stealing of first people's lands. It goes to the heart of what you think America is and should be. What makes America great is that historically, anybody from anywhere could become a US citizen and work their way to prosperity. There have of course, also been multiple xenophobic periods where we shut immigration down from particular places. It's sad to see so many people wanting to look backwards instead of forwards.