The problem with the argument is that it leans political: I think people are interested in just allowing people across the border willy nilly, without having to be stopped by such checks.
Otherwise, the ACLU might be similarly up in arms over DD checks? Wouldn't that be the case?
I try to be pragmatic about it:
+ If there's a high occurrence of Drunk Driving, then cops can do spot checks, esp. on long weekends.
+ If there are 'escaped dangerous cons' on the run, well, spot checks in a specific zone makes sense.
+ If there is a specific problem with large numbers of people who are in the country illegally travelling through - then random checks are a reasonable and proportional response to that.
Constitutional? Legal? I have no clue. But unless it gets really out of hand I don't see how it's totalitarian.
FYI I was never stopped randomly in the 5 years I lived in the US, and I was stopped quite a few times in France by the local Gendarmes. Sometimes obviously for DD checks, but other times I had no idea why but I had to show my passport and visa.