Politicians have to be gamblers
Politicians pretty well have to be gamblers. You give up a promising career in, say, dentistry, teaching or accountancy for a world in which all but a fortunate few are almost bound to end in tears. No matter how diligent and attentive a constituency MP you may be, if the national mood swings against your party, you will be voted out of a job. Your party may be taken over by a dominant clique of head-bangers with views alien to your own. Even if you make it through to ministerial office, some departmental disaster created by others may have you hounded by the media until you are forced to resign.