IT CAME to me in a flash of inspiration: Bertie Ahern and Ian Paisley are brothers under the skin. What's more, I realised, as I ruminated, Fianna Fail and the DUP in their bones are sister parties.
It was the magnificent shamelessness of the two lads that triggered the thought.
First there was Bertie on Saturday, merrily turning his back on all his pledges of fiscal prudence. FF won't be engaging in auction politics, poor Seamus Brennan had solemnly reported on Tuesday: they would not be matching the "unprecedented scale" of the Opposition's promises.
Then, four days later, Bertie proceeds to bet the Exchequer on the election: in Pat Rabbitte's words, he promised "everything bar a partridge in a pear tree for every family in the country".
Mind you, Ian far outclassed him on Monday. He, after all, did a volte-face on everything he'd been preaching for longer than Bertie's even been alive. "Verily," he said unto us, "No meant Yes."
Beguiled by Tony Blair ("We are both Christians, Ian"), by the gaily coloured beads that great seducer had given him (a peerage for his wife; a privy councillorship for himself), and by the glittering prize of having 'First Minister' on his tombstone, he sold out every principle he ever had about keeping unrepentant terrorists from government.
The man who has seen off every unionist leader who wanted to make peace with nationalism, sat unembarrassedly with the man who saw off every nationalist leader who wanted to make peace with unionism.
Both men know their parties will follow them blindly, for that is what their parties do. FF and the DUP have no time for dissent. FF is the only party in the south that likes to call its leaders 'Chief' or 'Boss'; in the 36 years of its life, the DUP has had no leader but Big Ian, who has wielded power like a particularly authoritarian pope. So both parties attract the obedient and the incurious; the corollary is that they loathe intellectuals.
Could Garret FitzGerald even have won a nomination for a FF seat? Or David Trimble been allowed house-room in the DUP?
Sure, FF has a first-class mind in my cousin Brian Lenihan, but a) he won a nomination because of family connections and b) Bertie has persecuted him for years precisely because he's threateningly smart. (For the record, I've met Brian only once, when on television he gave me the toughest opposition I've ever had in an argument about 1916.)
There is the DUP's Nigel Dodds, MP, who made the strategic error of getting a first-class degree at Cambridge, but who has since taken care to hide his intellectual credentials under a bushel of Protestant rhetoric. As Minister for Social Development in the short-lived Executive, he was alleged to have favoured Protestant areas when dishing out funding. Now, why does he remind me of John O'Donoghue?
Like their leaders, who have no interest in abroad, the two parties are essentially provincial. No FF or DUP politician worries about anything beyond the parish pump: Brussels to them is a place you procure goodies to take home to your supporters. Bertie could have been President of Europe, but he'd miss Drumcondra too much. Ian could have been a megastar in the US Bible belt (his honorary doctorate comes from the fundamentalist Christian Bob Jones University in South Carolina), but he'd rather crash around the small pond back home.
Bertie and Ian don't do vision like John Bruton or John Hume: they do pork-barrelling. Neither FF nor the DUP were around in 1912 when Protestants signed the Ulster Covenant, but their spirit was in the opening words: "Being convinced in our consciences that Home Rule would be disastrous to the material well-being of Ulster as well as of the whole of Ireland." It's no surprise that Bertie thinks the electorate can be bought, nor that it was the issue of water rates that made the DUP succumb to the British Government.
They'll have no trouble coming to terms with each other's nepotism either. Big Ian is desperately trying to secure the succession for his son: Bertie never had a moment's embarrassment about making his brother Noel a minister.
In negotiation, the DUP showed no more interest than did FF in ridding Ireland of paramilitary criminality. With Sinn Fein, it has reached an accommodation about splitting, not sharing, power. The Ulster Unionists and the SDLP had notions about governing for the common good, and Sinn Fein is grimly intent on ruling Ireland, but the DUP wants nothing more than its little fiefdoms. If an Executive can be cobbled together, DUP politicians will be content squatting in their backyards dispensing favours to the voters, with all the calculated generosity of John B Keane's archetypal FF TD, Tull MacAdoo.