Mitt Romney, the Republican establishment’s choice for the presidency, is fond of describing Barack Obama as an apologist for America. Few appear to be listening. Contrary to expectations at the start of Mr Obama’s term – and to continuing Republican hopes – national security is no longer a weakness for America’s “apologiser-in-chief”.

If the killing of Osama bin Laden earlier this year was not enough, then last week’s demise of Muammer Gaddafi and the announcement that US troops would be home from Iraq by Christmas should give Mr Obama electoral immunity on national security.

Pretty much the reverse applies to the condition of the American middle class. Their faith, it was widely supposed, would more readily invest in a Democratic president than any Republican alternative.