If there's one thing politicians of all ideological slants share in common, it's a talent for instant amnesia. They can forget what they said and did last week in order to say something entirely different this one.
at Rabbitte let that cat out of the bag with his infamous statement about making extravagant pledges on the campaign trail: "Isn't that what you tend to do during an election?" At other times, this tendency is even more problematic because what is being forgotten are not mere promises, but deeds which would cause most of us to lose sleep at night, to question ourselves relentlessly, to be crippled by self-doubt, and yet politicians forget those too.
Gerry Adams is the textbook example there. He has darker secrets than most; certainly more than those of his fellow TDs. The IRA committed some of the worst atrocities in the history of this island at a time when he was a senior figure within the republican movement. The fire bomb at Belfast's La Mon House, which burned 12 people to death, for example.
The DUP's Iris Robinson told the House of Commons that Adams was involved in that attack. Normally such an allegation could be dismissed using the famous principle popularised by Christopher Hitchens - "What can be asserted without evidence can be dismissed without evidence" - but, apparently, Sinn Fein approves these days of using parliamentary privilege to make accusations against people who can't defend themselves, so surely won't mind this one being repeated too.
Whether or not he was directly responsible, the SF leader was undoubtedly high up in the republican movement at the time. Does he lie awake at night, thinking about these atrocities? Agonising over wasted lives? He doesn't give the impression of doing so.
Last week, he even tweeted a nauseating little list of aphorisms, lifted from the sugary end of the internet, including the following gem: "Make peace with your past, so that it doesn't spoil your present."
He's fond of these sentimental, essentially meaningless mottos, such as one might find inside a Christmas cracker, and which are designed only to make people feel better about forgetting the past. "Examine your past so that it helps you make better choices in the present" would be wiser advice. The unexamined life not being worth living, and all that.
Any fool can ask questions of his enemies. It is the man who asks questions of himself who deserves respect, and Adams seems to think of that only as a distraction, an irrelevance. It would only hold him back. There's nothing more dangerous than a man who is untroubled by reflection.
War is one thing, but what of other personal tragedies? At a time when Adams was MP for West Belfast, and leader of the republican movement, scores of proven and alleged sex abusers were spirited across the Border and across the water. It is now known that many of these people abused other children, and that this was similarly covered up by the republican movement. There are countless stories of IRA teams being despatched from Belfast to other parts of the country to "persuade" victims to stay silent. Many of these people will not come forward publicly because they're afraid, but that doesn't mean they don't talk behind closed doors. The republican movement acted like any closed, authoritarian organisation. It protected its own. Does Adams never wonder about the children who were put at risk as a result?
His answer is that he knew nothing of this practice, but our polls suggest that the denials are not working. Respondents were asked directly: "Gerry Adams has stated that he does not know the identities of Provisional IRA sex offenders that were moved from the North of Ireland to the Republic of Ireland. Do you believe Gerry Adams in this instance or not?"
Six in 10 people (61pc) replied that they do not believe him. Only 17pc said that they did believe him, with a further one in five (22pc) saying they did not know. Hardly a ringing endorsement of the SF president's honesty on this issue.
They are right to be sceptical. Adams didn't get to the most senior leadership level in the republican movement by taking a hands-off approach to the struggle or by delegating major decisions to minions. It has been said that Adams knew of every bird which fell from the trees in West Belfast. It's a small place. People know one another and what's going on. The idea that he wouldn't have been told if certain named IRA members had been removed for being sex offenders is ludicrous. That's not how SF/IRA operated.
Only half of his own supporters, according to this poll, believe his claim not to know about these matters, though why they then continue to support a party whose leader they believe to have knowingly acted in such a way is for their own consciences to decide.
The obvious next question is to ask whether Adams has been damaged by this issue.
Again, the answers are stark. Over half (54pc) believe that Adams's reputation has been damaged by the scandal, and the figures are even starker amongst certain groups. An astonishing 69pc of Munster residents believe that Adams has been damaged by Mairia Cahill's allegations; as well as 67pc of Fianna Fail supporters and 65pc of the farming community, a group which seems stubbornly resistant to the appeal of SF as a whole.
Only 20pc purport to believe that his reputation has been undamaged by the revelations. Even amongst SF supporters, less than half think that he has been undamaged, and many of those may simply have said so out of loyalty, or a hope that might be so, rather than conviction.
What must be worrying for SF deputy leader Mary Lou McDonald is that her figures are only marginally better than Adams's. Asked whether the Dublin woman's reputation had been damaged by Mairia's allegations, 46pc of people said that it had, and again that figure rose to over half in particular demographics.
This is significant because Adams could not help being dragged into the Mairia Cahill story. He was one of the people involved at the time in how it played out. He met her on a number of occasions, the details of which remain to be clarified satisfactorily as his version of events keeps changing, and she made serious allegations about what was said in those private meetings.
He couldn't escape the line of fire, but Mary Lou deliberately chose to make herself a target by leaping self sacrificially between her leader and the incoming criticism. Any damage in her case was entirely self-inflicted. It doesn't look like a clever move right now.
There was one further general question about the party itself, which confirmed the trend. Over half of all respondents to this poll believe that SF has been damaged by the Cahill affair, with only a quarter disagreeing and a further 6pc answering, "it depends". Nearly one in five (18pc) said, 'don't know.'
This is significant too because what the latest headline poll figures show is that two parties are now effectively neck and neck - Fine Gael and Sinn Fein - with Fianna Fail only slightly behind. The next election is a three-horse race to be the top party, and any one of them could win it, depending on transfers and on the final seats in knife-edge constituencies deep into the count.
If a party has been damaged to the extent that respondents believe SF to have been, it can't possibly take those transfers, and crucial seats are lost. It's that simple.
This latest poll shows that SF has been damaged, and that it was Mairia Cahill who inflicted the killer blow, and there's probably no great wonder about that. Politicians have had far less controversial pasts than Adams's held against them, and for considerably longer. Voters did not say of these people, as SF wants voters to say about Adams: It was all in the past, things were different then.
Nor should they. The past matters, because the past is the best guide to the future.
What SF should do now is reflect whether the vicious all- out attack which it mounted against Mairia Cahill has been counterproductive. Beating up on rape victims is never pretty. It doesn't win friends, except amongst rapists and rape apologists. There were others urging a softer approach, but they were put in their place by hardliners whose principal loyalty is still to the IRA in Belfast rather than to the republican cause nationwide. How much damage is it worth suffering to keep these miscreants quiet?