The filibuster procedure in the US Senate has been used over many years to prevent decisions on many sensible matters. Next week, however, members of the upper legislative house may override the filibuster to support a deeply dangerous idea.

The Senate’s Democratic leadership has caved in to the demagogues and scheduled a vote on legislation designed to punish China for manipulating its currency, various incarnations of which have been floating around Capitol Hill for years.

A small mercy is that successive iterations of the legislation have become progressively less extreme. The earliest – an across-the-board tariff on all Chinese imports – has been dropped. Now the commerce department would be required to include assessments of currency undervaluation in calculating “countervailing duties” against allegedly subsidised imports.