> The statute apparently supporting Border Patrol’s authority within the border provides agents the authority to “board and search for aliens” on any “aircraft, conveyance, or vehicle” within a “reasonable distance from any external boundary of the United States.” (later defined as 100 miles in 1953)

> The regulation also provides exceptions to the 100-mile rule whereby the Commissioner of CBP or the Assistant Secretary for ICE may declare a larger distance to be “reasonable” on a case-by-case basis

> The same regulation also authorizes CBP to enter private property, other than residences, within 25 miles of the border without a warrant.

I know that's not 100, but I think it's still "less protection" than people would reasonably assume there to be.

> In cases testing the Fourth Amendment limits of Border Patrol’s authority to conduct warrantless searches of those entering the country at ports of entry (including functional border equivalents, such as international airports), the courts have used a balancing test whereby the Fourth Amendment privacy rights of entrants are weighed against the sovereign’s security interests at the border.31 The Supreme Court has decided that there is a reduced expectation of privacy at the border, holding that the government’s interest in monitoring and controlling entrants outweighs the privacy interest of the individual. Thus, routine searches without a warrant, probable cause, or reasonable suspicion are considered inherently reasonable and automatically justified in that particular context.

> Although nothing in the Fourth Amendment (or Constitution generally) provides for such a principle, this doctrine has become known as the “border search exception” to the warrant requirement of the Fourth Amendment. The precise limits to this exception are disputed and continue to be tested

How is this not clear that it is not a settled issue, and generally gives them greater permission to search (e.g. without a warrant) than say, a vehicle that's 500 miles away from any external boundary (at the least, a port of entry or international airport)?

You are quoting this article misleadingly. Obviously, there is a border search exemption to the constitution. But, as the article and the ACLU both point out, it does not apply 100 (or 25) miles from the border; it applies only at actual border crossings. The article is not about the border search exemption; it's about the "100 mile zone", which, as I said, more or less creates only the ability for CBP to do superficial immigration checkpoints.

I don't understand how you think you're helping anyone by making these kinds of claims. Who is better off believing that the government has sweeping search powers that they don't actually have?

> it does not apply 100 (or 25) miles from the border; it applies only at actual border crossings

I don't see how that's true because this law explicitly mentions 100 miles, three times.

https://www.law.cornell.edu/cfr/text/8/287.1

> The term reasonable distance, as used in section 287(a) (3) of the Act, means within 100 air miles from any external boundary of the United States

Surely I must be missing something?

At this point you're arguing with your own sources. You're going to need to take it up with them, not me.

I have to agree with parent, the quoted law very much establishes a 100 mile zone, as they said... and I still see zero evidence of it being "a myth". Plus you seem to be moving the goalposts and not accepting that.

I suggest you read the parent commenter's law review cite, which explains all these issues in detail. Or you can just go to ACLU's big page on this.