Thomas Friedman of the NYT points out the three aces held by Donald Trump in the U.S. election campaign of 2016. He could move to the centre in a campaign against Hillary Clinton and voters could give him a pass saying he only meant to start a conversation on immigration with his comment on the wall, that his comments on Muslims read carefully only means he would tighten controls on some countries, that he was acting in the way he said in his book "The Art of the Deal." A terrorist attack could change the atmosphere in the election and benefit Trump. And he could set a barrage of ads against Hillary bringing anti-Hillary Republicans back to his side after the divisions in a Republican convention. On the opposite side of this is Trump's penchant for making wild statements that could lead to a break with his support base, especially women who are shifting away according to some recent polls in mid March. Another vulnerability says Friedman is the rough way in which minorities are treated at Trump rallies, which could backfire with a serious incident resulting in hugely negative media coverage....