It is looking like telling lies is the prerequisite of becoming a politician. As a matter of fact, there is a way you will tell lies that people will start suspecting you to be a politician.  How we get to this point in human history is what no one can explain. 
I don't know about your country but in my country, politicians buy over media empires to sell lies and propaganda to the public... I know this is not peculiar to my country. This may be the reason there is a growing distrust between the leaders and the followers.

But is politics supposed to really be about lies? Why is the polity dominating by propaganda?