killers go free a week ago were orderly, as instructed by an African-American. "We're a nation of laws, so we respect the verdict that came down," Barack Obama said when asked about the case by reporters in Indiana. "Resorting to violence to express displeasure over a verdict is something that is completely unacceptable and is counter-productive."

Spoken like a graduate of Harvard Law School! In fact, Obama's white rival for the Democratic nomination, Hillary Clinton, put more juice into her press release: "This tragedy has deeply saddened New Yorkers - and all Americans. My thoughts are with Nicole and her children and the rest of Sean's family during this difficult time. The court has given its verdict, and now we await the conclusion of a Department of Justice civil rights investigation."

Obama is now well-advanced along the path of reassurance, where each candidate nearing the White House makes clear their fidelity to the standard of irrational violence. As with McCain and Mrs Clinton this year, he has affirmed his willingness to wipe out

America's enemies with nuclear bombs and missiles, though he drew some rebukes for saying he was not in favour of nuking the Hindu Kush, thus casting a disquieting flicker of reason across the path of reassurance.

Since he is, though half-white, black in appearance - and in such matters appearance counts for everything - Obama has dealt with the pigmentation problem by declaring that race is no longer a troubling factor in America, and should be low on the fix-it list of any incoming President. In Selma, Alabama, he declared that blacks "have already come 90 per cent of the way" to equality. Indeed he's already issued white America a loss damage waiver: "If I lose, it would not be because of race. It would be because of mistakes I made along the campaign trail."

Actually, if Obama loses, he will probably ascribe it privately to a mistake he made 20 years ago when he stepped into the Rev Jeremiah Wright's tumultuous church in Chicago instead of praying sedately in some dour white Presbyterian chapel.