There you start to get into the weeds of case by case opinions, the “reasonableness” of their restrictions, the willingness of stores to stir up the ire of activists of whatever stripe vs the inconvenience to their patrons, and the willingness of police to get involved. There’s a large body of federal case law on this, and there are state level laws as well. But as for a government facility like this DMV, there’s a case called US v Kokinda about post offices that is pretty on point.
US v Kokinda had to do with violation of a Federal statute, 39 CFR 232.1(h)(1)(1989), which prohibits “soliciting alms and contributions ... on postal premises.” This was on state (not federal) land, and there was no solicitation involved. Plus, they are not charged with solicitation, only trespassing. The men were outside, standing in a planter area, not impeding/obstructing anyone. How do you get a trespass conviction out of that, when there were others on the property at the same time?
602 states:
Except as provided in subdivision (u), subdivision (v), subdivision (x), and Section 602.8, every person who willfully commits a trespass by any of the following acts is guilty of a misdemeanor:
Subdivision (q) states:
Refusing or failing to leave a public building of a public agency during those hours of the day or night when the building is regularly closed to the public upon being requested to do so by a regularly employed guard, watchman, or custodian of the public agency owning or maintaining the building or property, if the surrounding circumstances would indicate to a reasonable person that the person has no apparent lawful business to pursue.
My guess is the State will argue that the DMV building includes the planter area where the defendants were standing, and that since they were preaching (had no apparent business to pursue) during regularly closed hours and refused to leave when asked by the CHP officer, then they are guilty of misdemeanor trespass.
The hurdles will be convincing the judge that 1) the planter area is part of the building, and 2) the CHP officer is a "regularly employed guard, watchman or custodian of the public agency owning or maintaining the building or property." I can see that approach possibly succeeding with the judge. The irony is that if they had been preaching during normal business hours, or if, for instance, they were going to renew their registration that day (and thus had lawful business to pursue), they could not be convicted of trespass!
I just noticed that the news article says the defendants were first asked to leave by a DMV security guard before the CHP got involved. I think they’re toast.