Trump is taking advantage of unspoken norms that include a respect for the office he holds, as he knowingly runs rough shod all over it. Maybe this explains why he’s able to get away with so much. It’s not that people are afraid of him. It’s more that he, simply, is the POTUS. There is power inherent in the office. And Trump has abused that power, bigly. He’s also being played.
I can’t say for sure that he is rotten to the core, but there isn’t much worth saving. There are times, though, when he evokes a certain sympathy, but only because he appears to have missed out on so much that would have made him more fully human.