In any organization - a church, a business, government or just a family - the climate comes from the top. The people become like their leaders. So, for example, if the wicked are in charge, sin will prevail.
Public morality is impossible without knowledge of God. He is the only source of truth and knowledge about what is right and wrong. so if the leaders don't know Him - or don't consult Him, they'll themselves be deceived about their own leadership - and so will the people that follow them.
People in leadership who anesthetize themselves with alcohol or other vices will eventually compromise their own principles. The fact that they are willing to turn to vices like alcohol or sex proves their selfishness and self-centeredness above all else.