America was once the great middle-class society. Now we are divided between rich and poor, with the greatest degree of inequality among high-income democracies. The top 1% of households take almost a quarter of all household income--a share not seen since 1929. An economy this lopsided cannot prosper. The poor and working classes are squeezed. The rich are increasingly absenting themselves from the country's troubles. Their businesses sell goods and outsource jobs to China; their homes are behind gated walls; much of their corporate income is in offshore tax havens.
It should be no surprise that our politics are foul as...