AIPAC is viewed as one of the three most powerful lobbies in the US capital, the others being the gun and tobacco lobbies. The decision at its annual meeting in Washington eases the way for Congress to back a Palestinian state. AIPAC has traditionally had a strong bias towards the right in Israeli politics and only grudgingly accepted the Oslo accords with the Palestinians in 1993. It seems to have moved quickly into line with Ehud Barak, Israel's prime minister-elect.
The lobby also wants to defuse allegations that AIPAC breached its official neutrality during the Israeli election campaign by inviting Benjamin Netanyahu, in his capacity as prime minister, to speak to it between the expected two rounds of voting. In the event, there was only one round, in which Mr Barak triumphed, but he refused to take Mr Netanyahu's place as a speaker.
Mr Netanyahu was expected to take a back seat after the election, though he is still prime minister until Mr Barak forms his government. Nevertheless, Israeli security officials are astonished at how Mr Netanyahu has ceased to function since election night. He holds no meetings of the cabinet or even the inner security cabinet.
A senior Defence Ministry official was quoted as saying he "has completely stopped being interested in government matters and security".
Mr Netanyahu, once the hero of AIPAC, has disappeared from political life, locked in his house in Jerusalem and rarely leaving it. Tomorrow he will resign from the Israeli parliament and take to the American lecture circuit.
Few political careers have ended as abruptly as that of Mr Netanyahu, prime minister for three years before his crushing defeat in last week's election. For him a comeback will be difficult after a campaign that focused largely on his divisive and quarrelsome personality.
Israelis express little interest in Mr Netanyahu's fate. When they do speak of him, it is usually to speculate about whether he will stay married to his wife, Sara, and how much money he can make lecturing in the United States.
The Israeli right, which once saw him as the political magician who gave it power, now blames him for its worst political defeat in a generation. His party Likud, devastated in the election, has special reasons for distancing itself from Mr Netanyahu. It wants to enter a coalition government with Mr Barak.
Mr Barak in turn is waiting to see if he can force both Likud and Shas, the ultra- orthodox party, to swallow his political agenda in return for a share of power.
r Mr Barak's Labour party named Likud as its preferred junior coalition partner yesterday, a move reinforcing the prime minister-elect's cautious approach to Middle East peace talks. (AP)