Speech of announcing for presidential candidate

In Bill Clinton's speech, he criticized Bush administration: "Middle-class people are spending more time on the job, less time with their children and brining home less money to pay more for health care and housing and education. The poverty rates are up, the streets are meaner and ever more children are growing up in broken families. Our country is headed in the wrong direction, fast. It's falling behind, it's losing its way, and all we've gotten out of Washington is status quo paralysis, neglect and selfishness...not leadership and vision." Sounds like worse than North Korea. It also reminds me of somebody's complains about dentist. "Every new dentist I go, they always complain that the previous doctor has done a terrible job, and push for redoing all the crowns, cavities.

Presidential election is a hope for people to have some changes , which are true from macro views , but not macro ones . It gives people a sense of ( democratic ) satisfaction . Every new president is like a new brand of beer in japan : similar to its predecessors, but only slightly different, bringing forward greater expectations of tastes, hence stimuli to the market. As easy as human being to get bored of the same thing, beers like Heineken, Budweiser etc have been in the market for decades. If replacing a president every few years is a must, why do people need to try to kick the old ones out like a dirty mop?
All the candidates try to attack their opponents about their problems, and those of the current administration, if not running for the second term. But if each president can really solve the problems in the age of previous one , there should be less and less that remain. There are new ones due to environmental changes , but many old ones remain for centuries : organized crime, drugs , alcoholic , dv , fraud , misconducts by company , government official, etc . Even FBI can be utilized by the wrong hands . The laws can prevent many crime from happening , but but can never eliminate them. There are also always sophisticated crimes committed by circumventing the laws.