usa – Do US or Mexican authorities impose any sanction if a US LPR comes back from Mexico to the US after traveling to Mexico for non-essential reason?

I am not sure what exactly that article means by “crackdown” either. It is clearly talking about US authorities and not Mexican authorities. Some other news articles (such as this LA Times article) have said that non-essential travelers are sent to secondary inspection, so perhaps the “sanction” is the inconvenience of going to secondary:

Nonessential travelers, such as those going to visit family or the
beach or to shop, are now being referred to secondary inspection areas
for additional questions, Customs officials said. Border officers will
also “provide such travelers with educational material in the form of
the Centers for Disease Control and Prevention Travelers Health
Advisory Notice to ensure effective understanding of travel

It’s kind of weird that they are talking about US citizens or LPRs returning to the US after non-essential travel, since the regulation on entry restrictions on the US-Mexico land border specifically defines US citizens or LPRs returning to the US as essential travel:

“essential travel,” which includes, but is not limited to—

  • U.S. citizens and lawful permanent residents returning to the United States;

which your article also alludes to, by saying that US citizens and LPRs cannot be denied entry under the ban. But if it’s not the ban, then I don’t know what other US law or regulation a US citizen or LPR going to Mexico for tourism and then returning to the US would be running afoul of. By talking about a “crackdown”, the articles seem to imply that CBP views such travel to be somehow “wrong”, but I can’t find anything official that says it is wrong (with respect to US law).