What about this approach?

If a person has stored (1) on his physical computer or (2) in the cloud, confidential correspondence that is protected under a recognized privilege (attorney-client, doctor-patient), then to grant consent to a search of this material destroys the privilege, as it would then be revealed to a third party.

Even if the information is unencrypted, if it is stored on someone’s proprietary device or private email, then they have a reasonable expectation that it is not public. Therefore, individuals who have confidential communications which are protected by privilege CANNOT consent to a search without destroying the privilege. It doesn’t seem reasonable to expect one to destroy such a privilege when crossing a border.

I’m not familiar with the interaction of selective searches and professional privileges. It would seem to me, though, that unless the search was a procedure everyone could expect to encounter when entering the country, then crossing the border does not imply/require disclosure to a third party of privileged communications.

It seems to me that a deportation appealed on the basis of refusal to consent to this sort of search, under these circumstances, would have to be overturned, so long as the privilege was recognized by the court.

Once a case like that drops, they’ve lost all ability to do any of these shenanigans.

Politicians and patriotic citizens are enraged that unfriendly individuals that attempt, say, bicycle trips in West Bank, are admitted to Israel. Note that so far, “pro-Palestinian organizations” are legal in Israel, but some members of the Knesset proposed to send them to detention camps. Even though these were not formal legislative proposals, this reflects the general trend toward intolerance. It starts with Prime Minister declaring that “delegitimization” is the gravest threat against the state, and NYT and Ha’aretz belong to most dangerous enemies.

And what if they want the e-mail password for the job-related server? This is outright forbidden security breach.

As I said, it is stupid for US government (and other governments) to allow for that. Simply reciprocal application of the procedures would suffice.

E mail messages are completely different from books you put in your suitcase, precisely because they are a form of mail; they are personal and private communications. I am very aware that many countries do not treat e mail in the same way that they treat normal mail, under the extremely dubious reasoning that they are text messages copied onto a server and therefore should be accessible to anybody who has rights to look at the server. I don’t agree with this, and think e mail should be treated like the normal post – but in any case I don’t agree that they are the same type of things as books or papers you might carry in your suitcase.

But I definitely agree that even if the state *were* to argue that the above powers could apply to computers (and you said you were giving them broad constitutional leeway…) – it most definitely could not apply to gmail accounts.