I am guessing that the reasoning behind this is that the border is considered to shift the threshold of "reasonable". About the only thing that even requires the loose threshold of reasonable suspicion is a body-cavity search.

Next, we have to look at how far the searches go... We can see that a box of written materials can indeed contain highly illegal contraband, and something that we would want to stop from entering the country. At the same time, that box of printed materials can also contain highly private data. However, under long-accepted and more-or-less non-controversial law, that box is quite searchable by a customs agent at whim.

So, why, when those same materials are put in electronic form, would these materials suddenly be subject to enhanced privacy restrictions? I cannot think of any legal reason that this would be the case. Perhaps the actual controversy is not the search, but the fact that a real search requires seizing the items. This is a new legal question, since a decent search of a box of magazines can be done in a few minutes, and the traveler can go on their merry way. Seizing a hard drive for a complete search, on the other hand, really sucks for the person that was hoping to actually use that hard drive.

What is the solution? The only one I can think of would be for CBP to make a copy of data if they feel the need, with strict retention requirements if no illegal material is found. Make the data "air-gapped", so the only way to get a copy out would be the issuance of a warrant.

What to do about encrypted data? That's a tough one. It can be just as illegal as our theoretical unencrypted contraband. The fifth amendment clearly states you cannot be forced to hand over the encryption key. However, locking stuff in a safe doesn't mean it cannot be searched at the border, so why would locking it on a hard drive exempt your laptop? For that, just rule that if you do not hand over your key so the data can be copied into our theoretically privacy-protected data store, you cannot bring the drive into the country either, and it has to be destroyed. (Yes, the current administration would just ignore the restrictions of any such law, if it did exist, but that is another matter entirely.)

Now, given all that, is it even worth the effort? Can't answer that one... that is what we have elected officials for, however imperfectly they serve.