Today President Obama signed the Matthew Shepard and James Bird Jr. Hate Crimes Prevention Act. At best, it's a feel-good law that will accomplish nothing. At worst, it will undermine the division of powers between the states and the national government by federalizing a wide range of violent crimes, further erode the constitutional ban on double jeopardy by inviting serial prosecutions for the same offense, and impinge on freedom of conscience, freedom of speech, freedom of association, and freedom of religion. The threat to First Amendment rights is twofold: 1) Like other hate crime statutes, the law imposes extra punishment based on defendants' beliefs, and 2) it could be used as an excuse to investigate and/or prosecute people for aiding and abetting hate crimes through provocative speech.