In my recent interview with Mary Lou McDonald, the President of Sinn Féin made the point that the next election, and probably the one after that, will be a housing election. The by-election caused by the resignation of former housing minister Eoghan Murphy will provide a test of McDonald’s hypothesis, though I feel she is right.  Dublin Bay South goes from Kimmage to Wood Quay, taking in Pembroke, Rathmines, Rathfarnham, and Terenure as it gets there. The constituency includes some disadvantaged areas like Mansion House A, but in general it is characterised by some of the most affluent areas in…