The government should not punish people for their beliefs. If Zimmerman had been known to espouse racist views, or if he had uttered racist epithets during his encounter with Martin, that evidence would be used to prosecute him for a federal crime that carries a life sentence. A man with different opinions would not face that risk. To make criminal punishment hinge on a defendant’s expression of politically disfavored ideas violates freedom of conscience and freedom of speech.

Federalism. The federal hate crime law allows the Justice Department to prosecute any violent offense allegedly motivated by bigotry when the defendant “interferes with commercial or other economic activity,” “otherwise affects interstate or foreign commerce,” or even uses a “weapon that has traveled in interstate or foreign commerce.” These ridiculously broad excuses for federal intervention make a mockery of the balance between state and national powers established by the Constitution.

Double jeopardy. Although the Supreme Court has held that serial prosecutions for the same actions do not violate the Fifth Amendment as long as they are undertaken by different levels of government, the “dual sovereignty” doctrine should not blind us to what is really going on here. A state jury acquitted Zimmerman based on his claim of self-defense. If the Justice Department decides to prosecute him, it will be saying that the state jury got it wrong.