Seldom in any democratic country can such fraternal hatred, such bloody-minded determination to eviscerate nominal colleagues, have been exposed within one political party.
Forget former British Prime Minister John Major's war with the Tory Eurosceptic "bastards" in the 1990s. Forget Republican primary attack ads in the United States. For eight days, leading members of the French centre-right have been ripping one another apart live on radio and TV or exchanging insults and accusations by Twitter.
Francois Fillon, the gently-spoken man who was Prime Minister until six months ago, has accused his leadership rival Jean-Francois Cope of turning France's largest political party into a "mafia". Cope has accused Fillon and his supporters of "massive, pre-meditated fraud" in an internal election for party president which ended in a near dead-heat last weekend.
A despairing attempt was under way to prevent the implosion of the Union pour un Mouvement Populaire (UMP), the party founded by Jacques Chirac 10 years ago (supposedly) to end 30 years of civil warfare on the French centre-right.
The man called in to mediate, Alain Juppe, a former Prime Minister and founding president of the party, said beforehand that he had "only a very small chance" of keeping the "small, flickering flame" of the UMP alive.
Like previous centre-right leadership wars - Chirac v Valery Giscard d'Estaing in the 1980s; Chirac v Edouard Balladur in the 1990s; Nicolas Sarkozy v Dominique de Villepin between 2002 and 2005 - the dispute is partly about ambition and personal loathing. But it is also a struggle for the soul of a French centre-right which has been left wandering in the moral wilderness by the defeat of Sarkozyism and the resurgence of a cosmetically cleaned-up but still xenophobic National Front.
A break-up of the UMP would trigger tectonic shifts, or linked explosions, in French party politics, which could lead to the emergence of a "new" centrist movement but also to a strengthened "far" or "hard" right.
The day after last Monday's election, Cope, 48, the party secretary-general, was declared the winner by 98 out of 170,000 votes. Fillon, 58, grudgingly "acknowledged" the outcome but said that the party had been "fractured morally and politically" by Cope's dubious "methods" on polling day and by his aggressive, hard right campaign.
In his appeals to the party faithful over the last four months, Cope had "out-Sarkoed" Sarko by using scarcely coded appeals to anti-immigrant and anti-Islamic, white middle-class resentments. Fillon had campaigned for frankly right-wing economic policies (such as the abolition for the 35 hour working week) but a more traditional, tolerant and "humanist" approach on racial and social questions.
Last Thursday, a bombshell arrived from the far side of the world. It emerged that 1300 votes from French islands in the Pacific and Indian oceans (which are constitutionally part of France) had been "forgotten" in the final count. Once they were included, Fillon won by 26 votes. Cope refused to step down. He accused Fillon of being a "bad loser".
Fillon announced live on television on Thursday that he no longer wanted the UMP presidency.
He simply wanted Cope's victory cancelled for the sake of "honesty" and "morality" and the credibility of his political "family".
The Cope v Fillon split sprawls across the old fault line of the French centre right.
The new division, represented by Fillon and Cope, is a split between moderate, thoughtful paternalism and feed-the-beast populism.
Cope, like Sarkozy before him, believes that the rise of Marine Le Pen's National Front can only be checked by red-meat appeals to national identity and fear of immigration and Islam.
Cope rejects outright alliances with the NF. Many of his supporters do not.
Fillon, though right wing on economic issues, believes the Sarkozy-Cope approach is electorally, as well as morally, disastrous.
Juppe, now mayor of Bordeaux, was due to meet both Fillon and Cope today at a secret location. If no deal emerges, Fillon could decide to pull up to 130 (out of 200) centre-right deputies out of the UMP group in the national assembly this week.
He has until next weekend to throw in his lot with a small, new centrist movement - taking the state funding with him and pushing the deeply-indebted UMP towards bankruptcy.
1976-1981: Valery Giscard d'Estaing v Jacques Chirac.
Chirac, fired as Prime Minister by President Giscard in 1976, ran for President in 1981, splitting the centre-right vote. Socialist Francois Mitterrand won.
1993-1995: Jacques Chirac v Edouard Balladur.
Chirac's long-time lieutenant, Balladur, became unexpectedly popular as Prime Minister from 1993. He ran for the presidency against his old boss in 1995. Chirac won and then defeated Lionel Jospin in the second round.
2004-2007: Nicolas Sarkozy v Dominique de Villepin.
Sarkozy betrayed his mentor, Chirac, to help run Balladur's campaign in 1995. He was never forgiven by Chirac or his right-hand man, Dominique de Villepin (who called Sarkozy "the dwarf"). Villepin was tried - but twice acquitted - of trying to smear Sarkozy as corrupt in 2004 to block his rise to power.