Since the terrorist attacks of 9/11/01, the United States has ramped up its Police Power influence. Their theory is that an increase in the surveillance and police presence will result in fewer crimes overall, and a harder environment for potential criminal and/or terrorist activity to remain hidden.
The most public example of this increase is the controversial Patriot Act, signed by President George W. Bush and renewed by President Barack Obama, which allowed greater scope for wiretapping, surveillance, and investigation into private and public citizens. While the common view of the Patriot Act is that it infringes on Constitutional rights to privacy, proponents claim that it only infringes when there is reasonable suspicion of crime. The debate is ongoing.
Another example is the increase in investigation into even small crimes. Because of the culture of suspicion, people are more likely to ascribe criminal intent to behavior by strangers, and the police are required to treat reports and claims as important. Many people have complained about unnecessary investigation after a small infraction, bringing the notion of a totalitarian "police state" back into the public eye. This idea is bolstered by the increased police activity on the Southern borders, intended to curb illegal alien activity, which is seen as dictatorial or needlessly brutal by opponents.
Overall, there has been an increase in police power in recent years. However, public disapproval and discontent with matters has affected both police ability to do their job, and government legislation and opinion on the matter.