Here are two just-heard stories that deserve a repeat. One first-hand, one second-hand, both from a credible source known personally for decades.
A Canadian-only university professor who has travelled widely (Asia, South America, Africa, Europe) felt disinclined to enter the Bush-era United States, and never did. After Obama, a 2010 flight south of the border. At the destination airport, treated like everyone else on the plane, the Canadian prof got fingerprinted. To round off the indignities, singled out for a full-body scan. No intention ever to enter that land again.
A neighbor of the above reporter, a provincial government employee, crossed the border about five years ago on a day trip, a previously common practice. The US border guard stood by the trunk of the car. When it was opened, the guard accused the driver of striking him with the trunk lid. Four hours of interrogation and harassment followed. Then one guard said to the other, “That should be enough for now.” That Canadian has not crossed the US border since that day.