Re: People who want to be politicians should not politicians.
If I remember my school classics correctly (It has been a long while, so apologies), the Ancient Greeks, when developing democracy, had two rules: One could not be a career politician, or a career orator (lawyer).
In court both sides had to represent themselves, one could ask someone else to represent you, but it must not be in exchange for payment of any kind. Plus said orator could not represent multiple people at once or in quick succession.
As for leaders, a citizen (rather than a slave) would be nominated for election. People would then vote from a list of nominees. This meant 3 core things:
1) The nominee lived in the society and were well integrated, so were relatively down to earth
2) You would have a pool of all people, including those who are not interested in seeking power for powers sake., to nominate from (unlinke now, where politicians are self selected for those who crave the power), and
3) Said nominee would have a business or job unrelated to their stint in politics/government, plus a social standing, that relied on the society continuing to function as well as before, or better
You would also go back to the society after your tenure, and if you did a lousy job it would be remembered by the rest, and would reflect on your social standing and family reputation. As such being chosen as leader was a privilege (if you do very well, it would increase your social standing in society), and a duty as a citizen to do a good job. It was seen as a necessary evil, rather than a career job for life kind of thing, as it is now.
Of course, the system is not without its problems, and you can argue whether it would scale to today's complex, global interconnected political societies, but even back then, thousands of years ago, the developers of democracy saw the inherent danger of politicians and lawyers to the system. Food for thought :-)