On the side of a quiet road a few miles out of the town of South Bend, in north-western Indiana, three men are preparing an assault on an icon of Roman Catholic America.

The men, activists from a radical anti-abortion group, plan the routes they will drive round town in trucks emblazoned with graphic images of bloody aborted foetuses juxtaposed with pictures of President Barack Obama. “Real Messiahs don’t support infanticide,” states one of their posters.