Examples of 2 public figures who have credibility and good ethics and have the power to influence people are:

Barrack Obama
Kofi Annan
These leaders served as a change agent for the society. They are inspiring, are visionaries, the torchbearers of new and improved society. Most striking feature of this leadership is the clarity of vision that they possess. This clarity gives them the conviction, which attracts people towards their ideologies and makes them their followers.

Examples of 2 public figures who do not have credibility or good ethics are:

Donald Trump
Narendra Modi
These leaders have less credibility associated with their name because while conducting their campaigning during elections, they made several promises and influenced many people towards their ideology. However, the promises were mere gimmicks and this disheartened the general public a lot.