J Street originally applied last August and what was expected to be a narrow vote in favor of its membership was postponed until February, an unusually long delay that the organization’s supporters blame on Heideman’s alleged reluctance to admit the liberal group. The delay allowed time for conservatives to organize and leverage their success in the World Zionist Congress election to stymie J Street, convincing the Zionist Supreme Court, a department of the World Zionist Organization that has jurisdiction over the AZM — that new right-wing representatives deserved to be seated before voting could take place on other new members.

Miriam Naor, the Zionist Supreme Court’s president, allowed the American Zionist Movement’s board to reconvene only after adding representatives from Eretz Hakodesh, a conservative Orthodox slate that was the breakout star of last year’s Zionist Congress elections, and the Zionist Organization of America. The total shift in power resulted in a swing of 22 seats for right-wing groups on the AZM board, which fluctuates in size but has roughly 150 members.

That series of rulings by Naor, former president of the Israeli Supreme Court, infuriated J Street and its allies. While the adjustment of board seats was tied to the election results, new representatives typically aren’t added until the American Zionist Movement’s annual meeting, which was scheduled to take place months after the vote on J Street’s membership.

“Because of these undemocratic and irregular steps,” said Shaina Wasserman, J Street’s community relations vice president, “we decided we no longer wanted to be a part of this organization.”

But Naor said in her decision that it was a simple matter of fairness: Eretz Hakodesh won seats during last year’s elections and should be allowed to weigh in on contentious decisions like J Street’s membership.

“In democratic elections, the wheel always turns, and turns again: Today’s outcome may be different from tomorrow’s,” Naor wrote, according to a translation of the ruling. “Each and every one of us needs to reflect on whether they would accept that others behave towards oneself as we have behaved towards them, when fortunes change anew.”

J Street, which was founded in 2007, has a close relationship with many top Democratic officials — then-Vice President Joe Biden spoke at the group’s conference in 2013 — and some Israeli leaders, though it is loathed by many on the right.

Morton Klein, president of the Zionist Organization of America, has been a longtime foe of J Street, criticizing what he described as its weak position on Iran, opposition to Israeli settlements in the West Bank and support for a Palestinian capital in East Jerusalem. Still, Klein said it was “pure coincidence” that his campaign to change the American Zionist Movement’s board composition came just before the planned J Street vote.

“If it did have something to do with J Street I’d be proud to tell you,” Klein said. “J Street is an anti-Israel, horrific organization and we will always fight them — but we fought this to get the seats we were entitled to.”

Weinberg, the Union for Reform Judaism vice president, suggested the series of delays that ultimately doomed J Street at least was due partly to what he described as Heideman’s recent personal animosity toward the Reform movement and liberal members of the organization. Heideman ran for chair of the Conference of Presidents last spring and Weinberg said he was furious that progressives did not support his ultimately failed bid. “He stopped reaching out to me,” Weinberg said. “It was pretty stark and drastic.”

Heideman said “there is no truth” to that claim, which he called “absurd, mean-spirited, insulting, offensive and derogatory.” Heideman declined to say whether he personally supported J Street joining the Zionist coalition, but said its application proceeded slowly for several reasons, including that members are meant to be nonpartisan, whereas J Street is a political lobbying group. Its more conservative peer, AIPAC, is not a member of the coalition, although the American Zionist Movement has participated in its policy conferences.

The question of who gets to participate in communal Jewish institutions is not a new one. J Street was at the center of a similar debate in 2014, when members of the Conference of Presidents of Major American Jewish Organizations voted against allowing it to join. And it’s not only left-leaning groups whose membership has been challenged recently. Liberal organizations unsuccessfully called on the Zionist Organization of America to be expelled from the Conference of Presidents last fall, citing disparaging statements made by Klein about another member group. In April, the Jewish Community Relations Council of Boston likewise decided against expelling the ZOA for “elevating white supremacist voices.”

Klein said the fact that both the Reform Movement and J Street supported his group’s expulsion from other Jewish forums demonstrated that they were “frauds” who were not sincere about building a “big tent.”

He also objected to some existing members of the American Zionist Movement, including Ameinu and Partners for Progressive Israel, which he said were “really hostile to Israel” and “anti-Jewish,” but added that he was resigned to remaining in coalition with them.

“As soon as I’m king of the world, I’ll make some changes,” Klein said.

Progressive Jewish groups frequently complain that establishment organizations like the American Jewish Committee, and coalitions like the Conference of Presidents, which is led by a former Republican lobbyist, do not represent the views of the overwhelmingly majority of American Jews.

Sophie Ellman-Golan, a spokesperson for Jews for Racial and Economic Justice, called the Conference of Presidents “antiquated and patriarchal” in an email to the Forward. And Bend the Arc, a progressive Jewish organization focused on domestic issues, said that the Jewish Social Justice Roundtable, a coalition with 70 member organizations, is “much more representative of the overall political beliefs and priorities of Jewish Americans.”

J Street is a founding member of the Progressive Israel Network, which has released statements countering those of some legacy Zionist organizations. But Ben-Ami said coalitions of like-minded organizations are no substitute for groups that can draw together Jewish groups with diverse views on Israel.

“A group like AZM or the Conference of Presidents is supposed to be an umbrella for people with all points of view,” Ben-Ami said. “If the AZM is only open to organizations that hold right-of-center views from now on they should just come out and say that — but don’t hold yourselves out to be the umbrella.”

The leader of the ascendant Eretz Hakodesh sees things differently. Rabbi Pesach Lerner said that it was J Street and other liberal Zionist organizations that had isolated themselves from the broader Jewish community by failing to “unconditionally support” Israel during the recent war in Gaza.

“If someone cannot support their family in time of war, perhaps they don’t really consider themselves part of the family,” Lerner said in an email interview. “You can’t have it both ways.”

Some of those who have been steeped in the domestic battle over who is allowed to speak on behalf of American Zionists look to Israel’s newly-formed “change government” as a model for drawing together disparate voices. If a hardline nationalist prime minister like Naftali Bennett can preside over a coalition anchored by a centrist party and that includes left-wing Meretz and Islamist Ra’am, surely Jews in the United States can embrace messy coalitions of their own.

Others, like Heideman, whose term as president expires this month, are less enamored with the election results. A comfortable majority of voters supported conservative parties and yet, Heideman pointed out, the Israeli right failed to shut liberal Zionists out of power.

“More people from the right voted than people from the left,” Heideman said. “The fact there is going to be a unity government is not one I’m going to comment on.”