The brain haemorrhage suffered by the Israeli leader has ended his reign and dramatically reshuffled Israeli politics, writes Peter Hirschberg in Jerusalem.
For weeks, the opinion polls have stubbornly refused to budge. With nagging predictability they have forecast an impressive victory for Israeli prime minister Ariel Sharon in the upcoming national election on March 28th.
Sharon has seemed infallible. Every action by the prime minister has simply seemed to fortify his position. Even the minor stroke he suffered two weeks ago failed to dent voters' confidence in him.
Shortly after 10pm on Wednesday that changed. The brain haemorrhage the Israeli leader suffered that night has effectively ended his reign as prime minister and dramatically reshuffled Israeli politics.
His exit from the political stage has thrown the race for prime minister, which he seemed to have sewn up, wide open. Israel's election campaign has started all over again.
The cardinal question now is whether Sharon's new Kadima (Forward) party, which he set up after leaving the ruling centre-right Likud in November, can survive without him. Until now Kadima has been a one-man party. Voters were drawn to it because of Sharon, who has been riding a wave of public popularity since he pulled Israel out of the Gaza Strip last August.
The secret of the prime minister's appeal has been his ability to tap into a widespread sentiment in the Israeli public - that it is not viable for Israel to continue ruling 3.5 million Palestinians, but that a negotiated settlement with the Palestinians, especially after the last five years of violence, is not feasible.
This made Sharon's unilateral approach - he left Gaza without negotiating Israel's departure with the Palestinians - appealing to so many Israelis. When he declared in recent weeks that there would be no further unilateral withdrawals in the West Bank, his supporters - most back further pull-backs from Palestinian areas - didn't flee Kadima. They simply didn't believe him.
No other Kadima leader commands the same appeal as the 77-year-old ex-general, or better embodies the mixture of scepticism, determination and pragmatism that has made him so popular among Israelis.
A snap poll conducted yesterday showed the party holding firm on 40 seats. But with the public only beginning to digest the full significance of the prime minister's illness, it is far too early to assess the true impact of Sharon's departure from the political race.
The odds-on heir to him in the nascent Kadima party is acting prime minister Ehud Olmert. He is a far less popular figure and his first challenge, if he is chosen, will be to ensure that the party, which attracted mainly Likud lawmakers but also several from Labour, does not splinter.
That is exactly what Labour and Likud will be hoping for. Sharon's decision to leave the Likud - because of the vociferous opposition of party lawmakers to his Gaza withdrawal - has left the party in a state of electoral meltdown. Polls in recent weeks have given the Likud 14 seats - down from 40 when Sharon won re-election in 2003.
Benjamin Netanyahu, the hardline former prime minister who resigned from the government in protest over the Gaza pull-out, will now be hoping he can persuade some leading Likud defectors to return home. Labour Party leader Amir Peretz, who has been languishing in the polls on 20 seats ever since Labour veteran Shimon Peres bolted to Kadima, might try to win the elder statesman back in a bid to bolster his position.
Peres made it abundantly clear, when he left Labour, that he was backing Kadima because it was headed by Sharon.
The prime minister, who for much of his political career was considered a pariah in the international community, is bowing out at a time when world leaders have been queuing up to shake his hand. If Israel's invasion of Lebanon, which Sharon directed as defence minister in the early 1980s, and the massive settlement drive he spearheaded, earned him the image of a warmonger, Sharon's decision to begin undoing his handiwork in Gaza, transformed that image abroad. Ironically, world leaders - including Egyptian president Hosni Mubarak, who has said on more than one occasion that only Sharon can make peace - will now be following developments with concern.
While Hamas leaders yesterday hailed Sharon's illness, calling him a "criminal" and "terrorist," officials in the Palestinian Authority were not celebrating. Some of them fear that there is no other Israeli leader who will be able to persuade the Israeli public to support further withdrawals in the West Bank.
That will be the main challenge facing Sharon's heir in Kadima: convincing the Israeli public that Sharon is not the only one capable of unilaterally disengaging from the Palestinians without ripping Israeli society apart in the process.