You've got to act like most politicians are clean and investigate and prosecute the ones who reveal themselves otherwise, regardless of what the ground truth is

You've got to act like most politicians are clean and investigate and prosecute the ones who reveal themselves otherwise, regardless of what the ground truth is. The "all politicians are crooks" line of thinking just gives the crooks a free pass while making it more difficult for whatever actors are trying to hold them accountable, whether for virtue's sake or for base political gain. Occasionally punishing a crook -- even if it is only a fraction of those deserving of punishment -- will make a few politicians of the next generation act a little less boldly, while shrugging your shoulders and saying "everyone does it" will make them ask what else they can get away with. Cynicism, even cynicism grounded in realism, doesn't make the world a better place.