IF, as seems increasingly possible, Barack Obama eventually fails in his bid for the Democratic presidential nomination, Monday 28 April may come to be identified as the moment when his campaign began to falter. Mr Obama had no particularly significant events to attend or speeches to make on Monday but in Washington DC at the National Press Club his moral mentor Jeremiah Wright made a speech that repeated and expanded on the criticism of white America that has led Obama to distance himself from the Chicago pastor to whom he has been close for 20 years. The Rev Wright, speaking to an audience of leading black political activists and an array of TV cameras, seemed to go out of his way to antagonise the white voters Obama will need if he is to get the Democratic nomination. He reiterated his “God damn America” message, and his assertion that the US government had developed the HIV/Aids virus “as a means of genocide against people of colour.” Mr Wright justifies this kind of talk by saying that the “black church” has different traditions from others. Perhaps, however, the most worrying of the Rev Wright's statements was his view that “Politicians say what they have to say and do what they do based on electability, based on soundbites, based on polls -preachers have a different person to whom they are accountable.” It did not sound like a ringing endorsement of Senator Obama's candidacy.