His invisible shield has deflected even the sharpest criticisms and most dramatic allegations. But, for the first time, his armour has been pierced by the latest barrage of ammunition.
The current spate of controversies are quite unlike anything Ahern has ever faced. Yes, the O’Flaherty controversy, which centred on the appointment of a disgraced Supreme Court judge to a top Brussels post, sparked uproar and saw his approval ratings plummet. But that was an isolated incident in the middle of a glorious economic boom.
This time, the fallout over his decision to appoint Ray Burke comes as the economy is on the slide and he is already bruised by claims his government deceived its way to election victory.
At a time when Fianna Fáil backbenchers need leadership, all they seem to be getting are weasel words and weak rhetoric.
You can see it clearly in his handling of the Ray Burke controversy, the man he defended passionately as an “honourable man” in 1997, but whom the Flood Tribunal described as a corrupt man who took hundreds of thousands of pounds for political favours.
So far he has said he has felt “ashamed” and “betrayed” at the findings of the report, but has yet to condemn his old political colleague.
And if you want more evidence of the Taoiseach’s laissez-faire approach to the appointment, just rewind back to his earlier explanations of the Burke affair.
His investigation of the North Dublin TD amounted to something along the lines of “have we anything to worry about?” Burke, naturally, said no. And that, seemingly, was that.
In a Dáil debate on May 28, over whether Ahern knew of a £30,000 (€47,720) payment to Burke prior to appointing him to Cabinet, the Taoiseach gave a number of different accounts in a story which collapsed under its own contradictions.
Explanation one: “On the day I appointed the then Deputy Burke as Minister I was working on the understanding that no money had been given to him.”
Explanation two: “I cannot recall if I asked him (Burke) if he received money from Murphys or JMSE. I was more worried as to what it was all about. In terms of my discussion with him, he did not tell me about that contribution.”
Explanation three: “Ray Burke told me the story before he came into this House to make the statement. The fact was that I then knew that Ray Burke had received a contribution of £30,000.”
All these comments were made on the same day, in the same location, during the course of the same debate.
All in all, it seems Ahern’s inquiries were never destined to get to the real truth. In the almost laughable investigation, his private investigator, Dermot Ahern, approached the benefactor in the alleged £30,000 payment The source of the allegation, James Gogarty, was never approached.
Now there is growing backbench discontent over the Taoiseach’s woolly treatment of this entire saga.
Bertie Ahern’s approval ratings have plummeted. Abounding rumours that a serving Fianna Fáil minister received a 100,000 payment, are only adding to the sulphurous whiff Add in a Nice Treaty campaign facing an uphill battle to get ratified and you see the euphoria surrounding Ahern’s election victory a few short months ago rapidly dissipating.
For the first time in his tenure as Taoiseach, the question of another leader is being discussed. The only serious contender being talked about is Brian Cowen, who disillusioned backbenchers see as the party’s strongman A meeting of Cowen supporters, who allegedly gathered in Buswells Hotel on Tuesday to discuss a plan to remove Mr Ahern, was probably more an attempt to turn up the heat than a serious leadership heave.
It is early days to be talking about leadership, or even the collapse of the Government. But the real point is that these issues are being talked about, and Ahern is on the defensive.
Ahern’s brand of non-confrontational, consensus-driven, ideology-free politics served him well in his career. This trait, once seen as an admirable facet of one of the most cunning, ruthless and devious of them all, is increasingly seen as a liability.
For once, the teflon is wearing off and Ahern will have to show his real leadership qualities if he doesn’t want any more mud to stick.