I'm slowly making my way through Paul Arthur's so far excellent tome of the relationships between Britain, Ireland and Northern Ireland - Special Relationships.
At the end of chapter two, "The Fatal Embrace," he notes an important characteristic of pre 1969 politics within in Northern Ireland:
...the most significant aspect of the party system was its degree of political underdevelopment, which manifested itself not in the two communities' 'inability to dominate' each other but their common vulnerability to internal factionalism; this in turn undermined their leadership's capacity to govern.
Such a scenario may still be familiar (at least up until the November elections) to activists in the two older party's that were the main subject of Arthur's attention: the Ulster Unionists; and now the SDLP, as direct successors to the old Nationalist party.
Is it possible that Arthur here points to the real reason for the apparent runaway success of the what are often described as the extreme parties DUP and Sinn Fein? That is, the ability to provide strong and effective leadership, an ability to dialogue with its support, and make deals with its opponents?