Though the advent of Oslo raised hopes among Israelis and Palestinians alike that a peace accord might work, inside AIPAC there was strong discontent with Oslo and its implications, and a lot of sympathy for hardliners in Israel, including Benjamin Netanyahu, the bitterest opponent of Oslo and its backers, including Yitzhak Rabin, the prime minister. As M. J. Rosenberg, a former AIPAC official, has documented, AIPAC moved steadily to the right from the 1980s onward. According to Weissman, that happened mostly because the group’s biggest donors were right-wing American Jews who identified with Likud rather than the Labor Party and other liberal Israelis. Many of its donors and some its staff split from AIPAC during the Rabin-Oslo era to work with more right-wing groups such as the Zionist Organization of America, says Weissman. After Rabin was assassinated by an Israeli extremist opposed to giving up the occupied territories, an increasingly right-leaning Israel and AIPAC moved more and more into sync. As Weissman tells the story:

“So Rabin is shot. I mean, he won Oslo in the Knesset by one vote! You could imagine that in America there was similar opposition [to Oslo]…. AIPAC had spent the last 15 years helping the Likud, so you’ve got people there that were sucking at the teat of Likud, that was how they viewed things. That’s why so many people left AIPAC. A lot of them went to join ZOA and a lot of them also contributed to the work of Daniel Pipes. When Rabin came in, they had taken their money and left, and there was a lot of turmoil. At the time, I remember, they’d send me around the country, to fundraisers, with a lot of older people, and I would be yelled and screamed at, ‘I can’t believe you’re doing this!’ Donors were leaving, taking the money, and that’s really their bread and butter, the lay leadership. AIPAC’s donors were very active in the organization. Very. They were major elements in making policy, in determining the agenda, who the leadership was.

[…]

“I tried my best to sell the peace process. But I tried to sell it in the context of what AIPAC was, that this was the way that Israel could become a permanent Middle East country. But the ideological war inside the Israel lobby, collectively, was extremely bitter — and very close, you know, the tally of votes was very close. I would argue that while most American Jews are probably center-left, the rich ones, the ones who give to organizations, the ones who are involved in politics, tend to be more to the right. Those are the ones who were close to the Israeli government when it was run by the Likud.”

Rabin, in his last years, was angry at AIPAC’s obstructionism, says Weissman. (According to M. J. Rosenberg, in New York Rabin met with liberal Jewish donors and asked them to help finance what become the Israel Policy Forum as a very small but not ineffective counterweight to AIPAC.)