I don't believe US politicians are any more corrupt than those of any other Western country, and neither should you.

I'm left wondering whether it's worse to have my head in the sand (in your opinion) or to suffer from paranoid distrust of the people you put in power by virtue of a democratic system you cleave to (in my opinion).

I belong to the first category of people because I consider that we have sufficient checks and balances in the UK to make sure that the "very bad" situation you dread is almost certain never to come about, and that's in a class-ridden country with an aristocracy which still controls the nation through its economy, regardless of what Parliament thinks, and where corruption is sanitised through the "Old Boy Network". If we have sufficient checks, then so have you.