I find from the Times of India that the chief minister of Bihar gets a basic salary of Rs 2000 per month -- less than that of a government peon -- though with perks it goes up to around Rs 25,000. You combine that relatively low salary with immense power and discretion -- and therefore opportunities to be corrupt -- and it's virtually a guarantee that the field of politics will attract either losers or thugs. And obviously the thugs will beat the losers.
Back in Indonesia, we have an anecdote that goes: "A government worker can have either two of these three qualities: loyal, smart, OR honest. One cannot have all three."
Of course, this does not apply to all.