Yeah, I don't generally have a problem with checkpoints for DUI, but I've become just paranoid enough to think that ICE is somehow behind or associated with this. Maybe not in Carlsbad, as the local cops don't cooperate with ICE except as specifically and in detail required by law and sometimes not then, but I could certainly easily see a situation where ICE could stand around at the checkpoint jumping on Brown people.
Carlsbad position:
Carlsbad, as part of San Diego County, follows the county's policy to limit local law enforcement cooperation with ICE, primarily by restricting assistance for federal immigration enforcement unless a judicial warrant is present, a stance reinforced by California's TRUST Act and county ordinances like the "CLEAR" proposal, aiming to build community trust and protect immigrant residents.
On a somewhat related issue - throughout our travels, maintained a private post office address. You use the address they assign you and your mail goes there. You can see online what you get and instruct them to shred, store, or send to wherever you are. To use these, you have to fill out a PO form 1583, and get your signature notarized. Well, I can't tell that the requirement nor the process has been changed but for some reason the Postal Service wants (requires) everybody to renew, i.e., complete new forms. I can't help thinking it's another attempt at ICE dirty tricks.