"Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted." - 8th Amendment of the United States Constitution.
It is legally impossible to be charged with just a hate crime without being charged with another crime, therefore hate crimes are in violation of this Amendment. They simply add to bails, fines, and sentences to existing crimes, when without them, most of those crimes carry harsh enough punishments as it is. In fact, many of those crimes cases already carry the strongest punishments allowed by the states without the hate crime laws anyways!