One of the functions of politicians in recent decades seems to be being public cheerleaders - Churchill in modern guise would have said something like "I have nothing to offer you but some pretty good results that will be quite enjoyable"
It's very easy to blame the politicians, the average American has led a largely comfortable, coddled life and is unprepared to hear anything negative. Politicians are also sales-persons and they tell the public what it wants to hear.
That's because it's a sure fire way to get elected in a democracy.