Most politicians are in it for 1) money, 2) power, 3) sex
I have had the unfortunate experience of frequently dealing with all levels of politicians from local to federal for several years. They have an attention span of a 5 year old with ADD issues and that level of understanding as well.
A person can be a subject level expert and the politician will expect them to explain something extremely complex to them in 60 second sound bite, of which they were only paying attention to 20 seconds. Then, the politician will consider themselves experts in the subject.
They vote along party lines and do what they are told.
I used to say that we could take random names out of a phone book and have better leaders than we elect, but we don't have phone books anymore, just like there are no good elected leaders.