For years, the vast majority of politicians in the main parties have avoided having honest public conversation about the extent and consequences of immigration. The fear of appearing racist, or giving any ground to the arguments of the far right, has left most MPs and commentators in Pollyanna territory - extolling the economic and cultural benefits of immigration and glossing over problems. That has done the nation no favours, because the consequences of rapid social change have been scarcely studied, let alone addressed. And it has increased many people's distrust of the political universe, as the gulf between their own...