Candidates promise to try to do things.
They often fail.
yes you want a leader who "trys"
They ALL (including Obama) promise to be "tough on China", but then they get elected and reality must be added to their rhetoric.
Often times a promise made on the campaign trail simply cannot be kept, and the maker of the promise is simply too naive to know better, especially if they've never held the office they seek. Every incumbent should be held to a higher standard on re-election promises.