You could dig up dirt on every single person if you catch them in their worst moments & you focus on just that detaching everything else he/she stands for.
If you want to evaluate a person, you have to understand how consistent that person is/was in their journey of life. Measure what that person saying/doing all the time for himself/herself. If all boxes tick in a positive way, all you can find is a powerful structure of a human being who stands for a purpose. Powerful people are driven by PURPOSE.