I suggest the simplest explanation of how Trump is different from other felons is right there in Wilhoit's observation on conservatism:

"In-groups who are protected by the law, but not bound by it, alongside out-groups who are bound by the law, but not protected by it."

He may have been convicted, but he faced no consequences. He was not bound by the law, so not only did his convictions and investigations not deter him, the lack of consequences emboldened him.