The purpose of borders is not to keep people safe. Borders do not prevent injury and death.
Borders are a bureaucratic convenience. By defining the area for which the public servants of a particular district or jurisdiction are responsible, borders minimize confusion and duplication. That is all.
To argue that borders are designed to keep people in or out of a particular territory is simoly to extent the notion that segregation is good to a larger body of land and/or water.
Yes, the Constitution empowers the national executive to keep track of migrants (remember migration is a natural human right), a necessary task, if agents of government are to be prepared to provide services to all persons within the Constitution’s jurisdiction. Gotta know how many there are, if services are to be provided.
Aye, there’s the rub. The people objecting to the arrival of more migrants on foot or in vehicles do not want to be providing services at all. What they want is to be giving orders, not providing assistance. Our agents of government seem not to understand that agents are supposed to act, to carry out functions —functions we, the people who govern, have defined as necessary.
How did the cadre of agents get turned into a clique of blow hards and verbiage emitters? That’s a good question. Instead of being overrun by technocrats, we have been swamped by technophobes.