The Guardian Protestant sectarianism in Northern Ireland is easy to spot. It parades its colours.
Catholic sectarianism is different.
It no longer has a theological component. It is a long time since republicans affirmed, as their forebears did, that Ireland was Catholic. The distinctive mark of a Catholic sectarian today is the demography argument. The sectarian demographic argument has long been part of the Sinn Fein calculation, and indeed it may be that some who knew better encouraged the IRA to imagine that the war was virtually won by force of numbers. Catholics are free people in a democratic system, entitled to judge for themselves what suits them, and they have the right not to answer the call of the tribe.