Apologies by politicians are not only rare; they are usually made out of self-interest when there really is no alternati ve. Witness Gordon Brown saying sorry to Gillian Duffy, who he dubbed a "bigoted woman" to a stray TV microphone for her views on immigration.
Nick Clegg's unexpected mea culpa on university tuition fees was different: he didn't have to do it. Indeed, some of his own advisers thought it would merely remind people of the fateful broken promise and smack of desperation and weakness rather than project the image of someone with the balls to admit his mistakes.
When I interviewed Mr Clegg for an hour yesterday in his spacious Whitehall office, he seemed like a man relieved to have got a long-planned apology off his chest. Before making it, he did not expect plaudits from an almost universally hostile press. He thought he would probably be vilified and mocked, and he was.
How did he make what was a very personal decision? After the 2010 U-turn on fees, Mr Clegg was public enemy No 1 and attracted protests wherever he went. On police advice, he reluctantly abandoned the regular town hall meet-the-people events he has always held since becoming Liberal Democrat leader.
This summer Mr Clegg quietly reinstated them as he visited all regions of the country. He found the mood different, even in university towns. He wasn't welcomed with open arms but he wasn't heckled and shouted down.
He did not conclude that the controversy over the broken promise was over. But he judged a subtle shift: time had healed some of the wounds, and some people were a little more open to listening to the argument for the policy. He even managed to turn round one audience in Cambridge as he spelt out that, despite a million headlines about £9,000-a-year tuition fees, there are no up-front fees and that repayments kick in only when graduates earn £21,000.
How Mr Clegg now wishes he had fought harder for it to be called it a "time-limited graduate tax" (which it is). Complicated Treasury accounting rules and the Conservatives' phobia about bringing in new taxes prevented that.
But to defend the details of the policy to the nation as a whole, Mr Clegg believed he had to try to throw off the millstone attached to it: his party's breach of its 2010 election promise to vote against any rise in tuition fees. Hence the apology for breaking the pledge, but not for the policy itself.
It was made in an honourable way. Mr Clegg took the rap all for himself. Many politicians would have tried to spread the blame. The Lib Dem leader would have been within his rights to remind us that the minister in charge of university funding is Vince Cable, the Business Secretary, who has somehow managed to avoid the flak for policy he introduced. It must have crossed Mr Clegg's mind, especially as Mr Cable appears, in the words of his Cabinet colleagues, to be "on manoeuvres" as he puts himself in the frame as the next Lib Dem leader. But Mr Clegg took it all on the chin.
The apology was the right thing to do. It might not look great now, but it just might look different in six months if it gets the Lib Dems more of a hearing for their other policies. Some voters will never forgive them for joining forces with the Tories. Others may be more open-minded.
This is their target audience. Mr Clegg has nothing to lose but the chains still tying him up in knots because of that broken promise.