Mr. Obama's claims are as dangerous as they are dishonest. People won't "be harassed" when taking their children out for ice cream because of what they "look like." The law specifically bans picking up someone just for being Hispanic or originally from another country. Instead, anyone arrested for a crime must have his immigration status determined before being released. It thus is not only Hispanics who will be required to provide evidence of citizenship, but everyone - whites, blacks and Asians included - who have done something wrong.

Police can't simply "ask somebody who they have a suspicion might be an illegal immigrant for their papers." Two conditions have to be met. First, police must have "lawful contact," meaning officers must already have detained an individual for violating some other law. Even then, authorities must have "reasonable suspicion" that someone is an illegal alien. This is a standard from the 1960s that police already deal with every day. In a border state such as Arizona, with half a million illegals, the vast majority of undocumented immigrants are going to be Hispanic, but the reasonableness standard used by Arizona specifically requires circumstances aside from race or national origin.

All the hyperbole about "papers" undermines the difficult work of Arizona police by comparing the thin blue line to communist East German border guards during the Cold War. The truth is, the new Arizona law doesn't even require anyone to carry an ID; it simply stipulates that "a reasonable attempt shall be made, when practicable, to determine the immigration status of the person."

The president is playing with fire by misleading the nation to stir up racial tensions. He's a lawyer who knows what terms such as "lawful contact" and "reasonable suspicion" really mean. If blood is shed over this imbroglio, it will be on Mr. Obama's hands.