If there were a Richter Scale of Political Resignations, then prime ministers such as Margaret Thatcher, Harold Wilson, and Harold Macmillan would register at the very top—on nine.
Big beasts such as Conservative Chancellor Geoffrey Howe and Defense Secretary Michael Heseltine would register at about seven. Iain Duncan Smith’s departure, on the other hand, would probably score around six.
The work and pensions secretary’s departure is the sort of earthquake that would only inflict slight to moderate damage on solid structures but is capable of causing more severe problems for less stable edifices. Unfortunately for the Conservative Party, at least in the run up to the EU referendum, it fits all-too-easily into the latter category.
Duncan Smith can hardly claim to be in the same league as Geoffrey Howe—a genuinely quiet man who altered the economic and social destiny of his country. His resignation has clearly resonated, crystallizing the antipathy many Tories feel toward a chancellor they see as too clever by half and a prime minister they regard as far too desperate to keep the U.K. in the EU. But Howe’s resignation really detonated, blowing a decade of British politics to kingdom come by triggering the defenestration of an icon and the eventual defeat of the Conservatives by New Labour a few years later.
Still, while Duncan Smith’s departure doesn’t represent a direct threat to a sitting prime minister, like Howe’s did, it is nonetheless a direct hit on the prime minister’s entire political project. It strikes at the heart of Cameron’s attempt to persuade the country that it can trust the Conservatives to combine competence with compassion and that it should vote to stay in the EU.
