It's not a new idea - I remember Robert Harris mentioning it in the Sunday Times perhaps 20 years ago. It's the theory (paradox?) that British prime ministers are brought down by what was supposed to be their greatest strength.
Eden: huge foreign policy experience, Middle East expert, Persian and Arabic speaker - resigned following self-inflicted Suez crisis.
Wilson: brilliant academic economist, technocrat - remembered now for presiding over a notably stagnant and crisis-ridden period in British economic history.
Heath: A meritocrat from a modest background, seen as someone who could connect the Tories to a wider public - his premiership saw very poor industrial relations and even concerns that British democracy might collapse.
Thatcher: Ruthless Iron Lady, crusher of Galtieri and Scargill - laid low by the plotting of backbench non-entities.
Major: A moderate, a conciliator - his time in office was characterised by Conservative Party factionalism and infighting.
Blair: Darling of the bien-pensant classes - now reviled by them.
Brown: All-conquering clunking fist, supremely assured economic maestro - we know how it ended.
So, how will it end for Cameron? In other words, what's seen as his greatest strength?