The Overton Window [1] says this is exactly what will happen.
There's a great video [2] about how this applies to Trump (which is where I first heard about it) and gives a good example of what "shifting the Overton Window" looks like.
The problem is that digital paper isn't paper, and while you can be charged with a felony for bypassing a computer's access controls, the law doesn't respect those controls at all. Your electronic documents have to be in your home or in your direct control to be protected.
Which is funny, because paper correspondance does not have to be in your home or in your direct control to be protected.
The Fourth Amendment says the same thing. It has been under relentless attack from the Supreme Court, but one senses a change in the weather...
Why are we now debating the privacy of encrypted correspondance from a baseline of no privacy for unencrypted correspondance?
What says we will not continue to accept more and more, as long as it is only a small step from status quo?