My perspective is coloured by where I live, so maybe where you live, things might be different. Well, answering the question simply. NO, there cannot be an honest politician.
There cannot be an honest politician because such a person will be out of politics even before he or she gets in.
With having a criminal record being a necessary qualifications for becoming a politician today, how can an honest person become a politician. If by some miracle he does get into politics and succeeds to get elected by the people in any capacity, the hordes of dishonest politicians will pounce on him and strip him of his honesty, dignity, integrity, will to live and ultimately his very life, in a very short period of time.
Actually if you are honest, manipulating people will prick your conscience, and politics is all about manipulating people, so there you are a resounding NO.
Yet, I sometimes wonder if one honest and just person manages to attract a hundred honest and just people (meaning the complete population of such people on our planet), could he survive and become the leader of a nation?