NBC News reports that American citizens are now occasionally being held at borders and electronics searched for some time, as in this story. Most of these citizens were Muslim but were native born.
The video told the story of a young couple held when re-entering New York State from Canada.
This is not considered a violation of the Fourth Amendment if it happens at a border. But the misuse of data later without court supervision would be a constitutional issue.
These incidents did increase after Trump’s inauguration.
In May 1997, I drove across the border from Montana into Saskatchewan along dirt farm roads because I had forgotten my passport (they could ask for a birth certificate then -- but this was before 9/11). I don't think you can do that now. (Or maybe migrants do.)
None of this would apply to routine security screening of electronics items before getting onto domestic planes. Ability to travel without damaging laptops especially would always remain a critical issue.