There was a time when federal crimes were few. The Constitution mentions only three: treason, counterfeiting and piracy. Fast forward 220 years, though, and you find that Congress has declared more than 4,000 offenses to be federal crimes.

For some lawmakers, that's not enough. They want to make a lot of violent crimes into federal offenses, if the perpetrators are so vile as to entertain certain thoughts while plotting their deeds. You could call it the "Criminal Mind-Reading Act," but it passed the House last week as the "Local Law Enforcement Hate Crimes Prevention Act" of 2007. The Senate could take up a similar measure any day. President Bush has promised a veto.

The bill would greatly expand the reach of existing federal hate-crime law. It defines "hate crime" so broadly, that actual "hate" isn't even required. One provision would make certain common crimes federal cases if the defendant intentionally selects a victim "because of the actual or perceived religion, national origin, gender, sexual orientation, gender identity, or disability of any person."

This may seem reasonable. But consider the all-too-common crime of a thug who spots an elderly lady using a walker and targets her for a mugging. Did he select his victim because she is (a) a woman and (b) disabled? Sure. But does the preference to prey on the vulnerable make the mugging a hate crime? Similarly, most sexual predators choose victims based on gender. Should almost all violent mugging and rape prosecutions be handled by the feds?

Such wholesale "defining down" of hate crimes would quickly swamp federal law enforcement agencies. This would leave significantly fewer federal resources devoted to fighting organized crime, terrorist plots, kidnapping and interstate scams of all stripes. The net effect would be less security for all.

And for what? The criminal act is already a criminal act. Declaring the mugging a hate crime does nothing to help the victim.

Well, proponents claim, it would reduce crime. The NAACP used this argument in the 2000 elections, when it ran an ad lambasting George W. Bush for not supporting hate-crime legislation in Texas. Their example: the appalling death of James Byrd, a black man murdered by white bigots two years earlier.

But murder was already a capital offense in Texas. Byrd's killers surely knew that. If the prospect of getting the death penalty didn't deter them, how would adding a lesser federal penalty?

Finally, we need to ask if it's really necessary to "federalize" hate crime. No one has made the case that local and state law enforcement officials are failing to prosecute hate-filled criminals. Indeed, many states apply stiffer penalties for those convicted of hate crimes than the federal legislation provides.

In criminal matters, what matters most is the act itself. Crime should be punished to the fullest extent of the law, no matter who the victim is or what the perpetrator thinks about that person. As Thomas Jefferson wrote in his famous letter detailing the separation of church and state, "The legitimate powers of government reach actions only, and not opinions."

Congress should want criminals prosecuted for what they've done, not what they believe. Federal attorneys are busy enough trying to lock up those who directly threaten our nation's security. Let's not force them to play thought police, too.

Ed Feulner is president of the Heritage Foundation.