If the kind of scandal that has beset Sinn Féin over the IRA’s handling of sex abusers within its ranks had happened with any other political party, it would have riven it apart.

But the violent struggle from which it has emerged makes Sinn Féin a special case.

Danny Morrison’s famous catch cry of “an Armalite in one hand and a ballot box in the other” has been updated for the post-conflict phase. The modern iteration is that the right hand does not know what the left hand is doing.

There was a strong sense of deja vu when Paudie McGahon revealed the details of his alleged rape at the hands of an IRA volunteer in Co Louth over 20 years ago.

First, there was a strong resonance in the manner in which the IRA had dealt with his allegations – down to the identity of the alleged head of the three-person IRA inquiry, Padraig Wilson.

When she made her allegations public last October, Maíria Cahill had also alleged Wilson, a senior Belfast republican, had played a leading role in the IRA’s inquiry into her allegations. Through his solicitors, Wilson has denied both allegations.

If that was not enough, the response of Sinn Féin's representatives to the BBC Spotlight programme was almost an identikit of its response to the Cahill allegations. Its representatives believed – indeed had no doubt– the crime occurred.

Limits of trust

But that’s as far as their trust in the victim went. They were to be believed up until the moment the crime occurred, but disbelieved from the moment after.

On RTÉ Radio's Morning Ireland on Wednesday, party leader Gerry Adams said he believed McGahon was raped but, when asked if he had been brought before an IRA kangaroo court, he said he did not know.

On Newstalk's breakfast show, the party's justice spokesman Padraig Mac Lochlainn said more or less the same thing.

There are many loose strands to the Sinn Féin explanation. For example, who arranged the IRA court martial or kangaroo court?

On Wednesday, Louth councillor Pearse McGeough said he had offered to accompany McGahon (and another unnamed man who made similar rape allegations against the IRA man) to a local Garda station.

Yet, he remained silent on who arranged the IRA court martial, or indeed if one had taken place.

Former Sinn Féin TD Arthur Morgan met McGahon at a much later stage, in 2008 and 2009. He said on Wednesday McGahon had seen the alleged perpetrator at a stadium in Dublin (presumably Croke Park) and was concerned he was back from exile and in the jurisdiction.

Default strategy

Morgan confirmed McGahon had referred to an inquiry but could not remember the specific term he used, although he was adamant McGahon had not referred to a kangaroo court or a court martial or used a “quasi-military term”.

But Morgan’s confirmation that a form of inquiry had taken place is significant, and seems to be in contrast to the ambivalence of his colleagues.

The standard response from Sinn Féin representatives is that if you wish to find out about IRA matters you need to speak to the IRA.

Unfortunately, P O’Neill is not always available to handle media inquiries. That deliberate compartmentalisation – the left hand not knowing what the right hand is doing – has become the default strategy for republicans.

Will this issue damage Sinn Féin electorally? Well, the party has not had a very good week, what with its change of stance on the welfare legislation in the North, which was seized upon by opponents as a “U-turn”.

Over the past year, there were the Maíria Cahill disclosures and the arrest of Adams in connection with the investigation into the murder of Jean McConville.

Sinn Féin's core followers will support it though thick and thin. Some might have agreed with the moronic tweet hastily withdrawn by Francie Molloy, its most recently elected MP, dismissing the McGahon allegations as "rubbish".

For some of the electorate, this will raise doubts. There are other and new considerations: McGahon is from south of the Border; there were no doubts over the integrity of the Garda as regards the case; the victim was highly credible with no axe to grind; and this was the second such case to emerge .

The party has been backfooted on it: Sinn Féin’s teflon coating with the southern electorate is wearing thin.