It is almost certain that Gerry Adams never intended to use the word ‘n****r’ as a racial slur.
The word is one which some black Americans have attempted to reclaim and therefore the context in which it is uttered is crucial to understanding the intended meaning.
Nevertheless, those six letters - particularly when uttered from a white politician’s lips - are politically toxic in the US and elsewhere.
Those who have supported Sinn Fein despite the allegations of Mr Adams’ former IRA comrades that he ordered the abduction and murder of a widowed mother-of-10 (he of course denies even being in the IRA, let alone ever sanctioning any murder), are unlikely to now abandon their leader over this row.
But it is the impact of the controversy in the US which is likely to concern Sinn Fein the most. Outside of Ireland, America is the engine room of Sinn Fein’s political success, funnelling money and moral legitimacy on republicans throughout the decades of the Troubles and then the long years of the peace process.
The sort of left of centre Americans drawn to Sinn Fein are more likely to be unsettled by this incident precisely because in the US republicans have always sold ‘the struggle’ as a moral one akin to that of Afro-Americans.
That knowledge will no doubt have hastened yesterday’s classic half-apology where Mr Adams said sorry to those who were offended by his “inappropriate” use of the word ‘n****r’ - but then went on to vigorously defend the sentiment behind the tweet.
In doing so, the Sinn Fein president probably revealed a far more controversial view than that which fails to realise that certain words are widely viewed as offensive.
Mr Adams explicitly and in detail explained that the plight of Irish nationalists was similar to that of African slaves. Among the “evidence” listed by Mr Adams was “partition”.
The idea that the partition of Ireland – as controversial and significant as it was for both Protestants and Catholics on either side of the border – was remotely similar to the situation of a people who were captured, shackled and traded in human markets reveals an exceptionally distorted view of history.