What's the most cynical profession ever ?
For me, politician. You have to exploit the worst low instincts of the people to get elect and say what they want to hear, even if you don't think a word about it, and you are not obligated to hold any of your promises.
Politician would definitely win. You have to really whore yourself out to be even remotely likeable if you want votes. You have to spend like crazy campaigning. You have to go around from town to town, actively making promises you know you won't keep. You lie your face off in every debate you're in.
Then if you finally reach a position, it's literally like a cushy job with, somehow, the bare minimum requirements. The worst you can do is just not fulfill your promises but then again, you lied enough anyways so what does it matter? You could get into trouble with authorities but again that depends on position and some political positions give you diplomatic immunity and if you're in one of those, then go ahead and break nearly all the laws short of killing people.
Politicians' key things to do is just talk, write on paper, sit for prolong periods to vote on things and basically just rely on other staff to do all of the dirty work for you. All at the expense of those they govern.