Offhand, Ulysses S. Grant had a scandal ridden presidency (1869 - 1877) with multiple large scale corruption examples all headed by his closest associates.

There was some goings on related to foreign territories and annexation that I don't well recall, but to this day Grant's degree of involvement is debated - he tolerated much corruption from his personal secretary, defended him, and steered corruption investigations away until eventually removing Babcock(?) from his post.

Much pressure was exerted during this period, I hazard some of that pressure was via threats to persons, their assets, and perhaps their families.

* https://en.wikipedia.org/wiki/Scandals_of_the_Grant_administ...