A leader can only influence others if he has credibility. In other words, if followers trust him, then he can influence them to accomplish a common good. Sadly, many leaders do not fully realize the importance of credibility. It is so hard to earn and yet it's so easy to lose. It can disappear in a twinkling of an eye. Credibility is fluid, not static. It can also depend on the whims of followers. The leader may have credibility today, but followers can still choose not to trust him tomorrow. The best that a leader can do is to develop his credibility over time, and hope that followers can choose to trust him.