Listen: Kingsmill survivor Alan Black’s moving testimony was final straw that convinced Sinn Fein McElduff issue wasn’t going away
Maybe it was the raw and powerful words of Alan Black on RTE that was the final straw for Sinn Fein and Barry McElduff.
Kingsmill's sole survivor has told the story of the horrific events of that night in January 1976 many times previously.
But perhaps for the first time, people on both sides of the border - who before may not have paid it enough attention - were truly listening. Only those with a heart of stone wouldn't have been moved.
Black's simple and eloquent account on Sunday with Miriam on RTÉ Radio 1 of how his 10 workmates were slaughtered on a south Armagh road and his struggle for sanity in the months and years afterwards was heartbreaking.
It was clear he is a man who harbours no hatred or bitterness in his heart. So when he said that McElduff hadn't just disrespected the dead, he had danced on their graves, it carried huge emotional and moral weight.
While the traditional republican grassroots remained behind the West Tyrone politician, his failure to resign was indisputably harming his party not just in the south but among its newer, softer base north of the border.
Sinn Fein and its MP will have finally realised on Sunday that the story wasn't going away. McElduff's three month suspension and even John O'Dowd's unequivocal condemnation of the massacre on the BBC on Thursday night wouldn't suffice.
The Shinners are set to elect their new president at a special ard fheis in Dublin in three weeks. They don't want to be organising that historic event against a backdrop of continuing media headlines about one of the worst sectarian atrocities in the history of the Troubles. And so on Monday morning, McElduff announced his resignation. It was a very different man we saw than the one clowning around with a loaf of bread on his head just 10 days earlier.
He looked utterly dejected. Michelle O'Neill said he had informed her of his decision to quit the night before. Whether it was entirely his own decision or, whether the party leadership pushed him along the way, remains unclear.
McElduff has certainly felt the pressure personally. He has been stunned by what he still insists was the unintended consequences of his video. His two daughters, Niamh and Blathnaid, staunchly defended him on social media.
Their efforts were reported by the press, and friends said McElduff was dismayed that his daughters were now also in the spotlight.
As a realist, he also has acknowledged that outside the republican community, he had been found guilty by a majority in the court of public opinion.
Sinn Fein is regarded as having one of the slickest and most professional PR machines of any political party in these islands but it has been found seriously wanting in the past 10 days.
It was shamefully slow to respond to the story at the start. McElduff's response to the growing outrage on Saturday, January 6, was three short tweets totalling 64 words.
His failure to come forward with a comprehensive account of what had happened late that Friday night - likely on the advice of the Sinn Fein press office, who believed it would only add fuel to the fire - condemned him in the eyes of many.
Over that weekend, the party leadership remained silent. Gerry Adams, Michelle O'Neill and Mary Lou McDonald didn't say a word. It would be inconceivable for Theresa May, Jeremy Corbyn, Leo Varadkar or Micheal Martin to do likewise in a similar situation.
On Monday, Sinn Fein's already flawed damage limitation strategy became disastrous. Declan Kearney's tough talk on BBC's Good Morning Ulster raised expectations that McElduff would be axed.
Michelle O'Neill's subsequent announcement that her MP would instead be suspended for three months on full pay was therefore seen as absolutely inadequate.
Again, McElduff appeared to have been gagged by Sinn Fein, saying only a few words to the press as he left the party's Falls Road premises before getting into a waiting car. While Sinn Fein publicly said it believed him over the video, the imagery that day didn't imply that.
Far from putting the story to bed, the tokenistic suspension made matters worse. Any punitive action against McElduff insinuated guilt yet the 'sentence' didn't appease unionists or a large swathe of public opinion.
The West Tyrone MP's greatest sin in the eyes of Sinn Fein leaders was that he made it difficult for the party to continue with the victim narrative it has developed over the past year.
They knew that every time Sinn Fein in future raised allegations of unionist ignorance or intransigence, its opponents would retort "Barry McElduff". As a DUP source said: "Barry neutralised Arlene's crocodile."
For unionists, the cartoon by artist Brian John Spencer depicting Gerry Adams shouting 'Equality' beside rivers of blood flowing from the Kingsmill minibus was a powerful image.
Ironically, Mr McElduff had been one of the most widely liked Sinn Fein politicians. He was an old school republican, joining the party 30 years ago as opposed to the more ambitious recruits of recent years.
The SDLP's Alban Maginness - an outspoken critic of McElduff's party - said he was popular at Stormont, "distinguishing himself from other, usually humourless, Sinn Fein politicians".
A graduate of Queens University, Belfast, McElduff once briefly considered a career in journalism before devoting himself full-time to politics. He has three grown-up children with wife Paula. A relative by marriage was one of the eight IRA men shot dead by the SAS at Loughgall.
McElduff doesn't drink alcohol and is a man of simple tastes. He previously told this newspaper that his favourite way of relaxing was sitting down with "a mug of tea and a newspaper". As "a traditionalist" he preferred a hard copy rather than reading the news online.
In 2016, he said politics required "you to be very tough and thick-skinned". His golden rule was to be himself "and don't try to impress anyone".
He said he was once advised that if you said something twice but people didn't agree with you "perhaps you should leave the whole thing alone ... you don't say it three times".
On Sunday night, McElduff decided that his message had failed and he had to go.
He once said that if he had to do something outside politics, he would like his own radio show "in the style of Chris Evans or Ryan Tubridy". That will never happen now, and it is ironic that it was perhaps a radio interview that contributed to his decision to resign.