Because the Founding Fathers purposefully used the word "People" in writing the 4th Amendment and choose not to use the word "Citizen."
Therefore, everyone in protected!
Are you saying once the people determine this is an invasion and not immigration, this will be when no protection will exist for the illegals?
Hmmmm....
I thought I remember the Preamble to be "We the PEOPLE of the United States", which didn't really say "we the citizens" of the United States, either.
There seemed to be a lot of common sense applied to the wording (if I recall it correctly from long-ago school days), and the INTENT was to provide a form of Government for the NATION, where those who lived in the country, or wanted to, would be required to take an OATH to abide by it.
Maybe those who have interpreted the Constitution should AMEND it to say "We the foreigners who have sneaked into the United States for freebies at others' expense", or words to the effect of how it has been mis-interpreted and mis-used?
The "people" or "persons" arguments don't even pass the smell test, yet Lawyers have used activist Judges to twist the words to fit their interest or THEIR personal bias.