Killian Forde was once tagged on the front cover of The Dubliner magazine as 'Sinn Fein's First Taoiseach?'
By resigning from the party and joining Labour, as he did last Friday, the Dublin city councillor certainly isn't suggesting that he's lost his ultimate ambition.
He has, however, belatedly realised that he can never achieve it with the Shinners -- and sent out another clear signal that Gerry Adams's party is going nowhere fast in the Republic.
The immediate reason for Forde's resignation is the controversial budget drawn up by the council, which he supported but his four SF colleagues opposed.
However, the underlying causes go much deeper and can be detected in his barbed complaint about the lack of internal debate within the party.
That's just a polite way of saying that SF members are terrified of doing or saying anything that might cause their leader even the slightest displeasure -- and while that kind of iron discipline might have worked in the past, its shortcomings have now become cruelly exposed.
Forde's departure is the third SF resignation from Dublin City Council since the local elections last June.
When you add that to the loss of Mary Lou McDonald's European parliament seat, it confirms that the party is on a slow, downward spiral of support throughout the capital city.
Unlike some of the other departures such as veteran Christy Burke, Forde cannot be dismissed as an old party hack whose best days were behind him.
In fact, the party once held him in such high esteem that he would have replaced Mary Lou in Brussels had she won a Dail seat in the 2007 general election.
Instead he will now become a feather in the cap of Eamon Gilmore (who is himself a former member of official Sinn Fein), who will see this as further proof that Labour is winning the long-term battle for Dublin's considerable left-wing vote.
One of the few SF candidates who did reasonably well in last year's elections was Toireasa Ferris, daughter of the convicted gun-runner and Kerry SF TD Martin.
Following her narrow defeat, she wrote an article for An Phoblacht in which she admitted that SF "means nothing" to the vast majority of people in the south of Ireland.
While that may have been flattering her colleagues a bit (those who have been on the receiving end of their violent tactics know exactly what SF stand for), her basic point that the party's organisation needed a radical overhaul was basically correct.
Instead of facing up to its problems, however, SF has clearly retreated into self-denial mode. Their four TDs are making virtually no impact in the Dail, where their irrelevance was recently highlighted by Arthur Morgan's stunt of getting himself thrown out of the chamber.
Despite the recent controversy over a suggestion that Fine Gael might form a coalition with them, the opinion polls suggest that it's highly unlikely Enda Kenny or anyone else will need their support after the next election.
Gerry Adams is now 61 years old and has more white hairs in his beard than black ones. According to those who know the man best, he is keen to stand down as soon as a credible successor can be found.
But with Mary Lou McDonald now in limbo and younger talent such as Forde and Ferris either quitting the party or told to shut up, it's hard to see where the next generation of leadership will come from.
Meanwhile, of course, the Sinn Fein leader still has serious questions to answer over the way he handled the sex abuse accusations levelled against his brother Liam -- with many people refusing to believe his protestations that the two men have been estranged for decades.
Sinn Fein have all the appearance of a party in terminal decline.
It couldn't be happening to a nicer bunch of guys.