
This is largely TDS hysteria on the basis that CBP has long had broad authority within a 100-mile border zone extending offshore into the territorial waters of the US. Some of this is codified at 8 CFR 287.1. Also 19 USC/CFR comes into play here as well.
The point is that the previous administrations open border policy has necessitated that Trump to extend this longstanding rule to the rest of the country that lives 100 miles inland (~60% of US population).
That said, nobody is in favor of warrantless searches but that's a consequence of our own making.
So for the 40% of people that live within 100 miles of the coast or an International border, your rights remain unchanged. For everbody else, welcome to the party pal.