What's Up With All The "Border" Checkpoints?

OK, I haven't been down near the border with Mexico in a few years so this may not be a new phenomena, but just going to Big Bend National Park and coming back north I was inconvenienced by three roadblocks. All traffic was stopped and had to be scrutinized by an agent, and I wasn't comfortable with the abrupt questioning about my business.

Here's the problem with this as I see it. First of all, these checkpoints, or more realistically, roadblocks, because the traffic was hindered for a period of time, aren't the border. These established policing stations are well within the territory of the US, in one case 60 miles. If you accept that these stoppages are necessary according to the government, then you have to assume that all that square mileage before the "checkpoints" isn't the USA, otherwise why did it take so long to see if illegal immigrants are stealthily sneaking into the country?

Of course the whole thing is a farce, as usual, entirely predictable from a mafia determined to establish a police state with a boot on everybody's neck. Border security has been a joke since forever, glaringly so since the cabal's 9/11 when "security" only meant their security from us, so virtually nothing was done for years about the Mexican border until the problem (meaning public outrage) became acute. This was when the manipulators decided to act, setting up their armed traffic outposts to get american citizens used to one more outrage - being scrutinized for no reason. Woe be to any concerned citizen who objects to traffic diversion and time lost to unconstitutional grilling.