In politics, there is a concept called “the Overton window”. It is named after the academic Joseph Overton and describes the range of politically acceptable opinions you are allowed to express in public. In Ireland, the list of such views grows shorter by the day.

Last week Peadar Tóibín, a former Sinn Fein TD who has established the political party Aontu, tried to push open the Overton window just a little by asking us to have a debate about “sustainable immigration”. He invited us, for example, to consider the effect of immigration on the cost of housing.

Straight away, Tóibín was slammed for trying to whip up anti-immigrant sentiment. We had Fianna Fail’s Timmy Dooley demanding that this “fringe party” be “confronted robustly” for daring