The America-Israel Public Affairs Committee, best known by its catchy acronym AIPAC, is a modern Jewish-American miracle. Anyone who has wandered the jarringly packed halls of its annual policy conference, which recently drew almost 20,000 attendees—among them 4,000 students—can attest to the sheer power and majesty of America’s preeminent pro-Israel lobby.

After being officially incorporated in 1963, the organization embarked upon a startlingly aggressive phase of growth, dispatching hundreds of field operatives to develop a vast and diverse network of grassroots support throughout all of America’s 50 states. By the 1970s, the organization had amassed the power to push for the State of Israel even against the policies of the president of the United States.

During an apparent clash between Israeli Prime Minister Yitzchak Rabin and U.S. Secretary of State Henry Kissinger, President Gerald Ford notoriously threatened to enact a “reassessment” of the American relationship with Israel, even noting in a letter to the Jewish state that “failure” to accede to specific negotiations would have a “far-reaching impact” on American “relations” in the region. The next day, the president received a letter of his own. This time, it was signed by 76 senators—six more than the supermajority needed to override any decision of the executive branch—and it demanded that the president “make it clear that the United States, acting in its own national interests, stands firm with Israel.” The House of Representatives followed suit, and the “reassessment” never happened.

Throughout the sprawling halls of the Capitol, the message was clear: AIPAC was in the building.

Fast-forward to 2016, and AIPAC would be renting Washington’s Verizon Center arena just to house the entirety of their policy conference keynote event, which featured Washington’s most powerful names, including then-Vice President Joe Biden, former Secretary of State Hillary Clinton, Gov. John Kasich, House Speaker Paul Ryan, and, of course, presidential candidate Donald Trump.

Today, AIPAC stands upon the sturdy support of 100,000 members and boasts a $72 million annual budget cushioned by a $140 million endowment. Some 300 staffers populate 18 AIPAC offices spread across the country. Its army of lobbyists has established deep, stable ties with State Department and Pentagon bureaucrats, and can instantly mobilize a vast network of political-action committees and government heavyweights.

Yet, even as the organization glimpses the very heights of its own success, it’s also beginning to face its most serious threats.

Like any centrist element of American political life, AIPAC has been besieged by the ever-intensifying political extremes. And amid this bitterly sectarian political climate, bipartisan behemoths like AIPAC have found themselves grasping in the dark for allies.

Most recently, AIPAC has hit snags in its relationship with the Trump administration.

When presidential candidate Donald Trump was invited to speak at AIPAC’s 2016 Policy Conference, he chose to punctuate an otherwise remarkably eloquent and comprehensive speech with the claim that Barack Obama was “maybe the worst thing to happen to Israel.” This, just after noting that at least the sitting president was “in his final year,” where after he proclaimed a clear and simple “Yay!” Much of the audience, clearly frustrated at Obama’s often turbulent relationship with the Jewish state, rose in mass applause. I was in the room at the time. The response to the comment was electrifying.

The very next day, AIPAC President Lillian Pinkus, choking back her tears, took to the stage to announce that “last evening, something occurred which has the potential to drive us apart, to divide us.” She went on to say that she and AIPAC’s leadership took “great offense” at the “ad hominem attacks … levied against the president of the United States of America from our stage.”

Perhaps unexpectedly for Pinkus, Trump would go on to win the presidency that November. Though Trump agreed to send his vice president and U.N. ambassador to address AIPAC’s conference that year, the love lost over the affair was lost on no one there.

Since then, AIPAC has taken a hit from the Israeli right, too. During a recent gala held by the Zionist Organization of America, Israel’s ambassador to the United Nations, Danny Danon, was reported by The Daily Beast to have “implicitly needled the mainline [AIPAC] … by saying that the ZOA was now the go-to organization in the U.S. for the Israeli government.”

The growing political roadblocks facing AIPAC in Washington are by no means limited to its relationship with the right. On the contrary, AIPAC’s alienation from American political extremism began years before the rise of Trump during the rocky years of Obama administration. Back then, the pro-Israel body found itself being excoriated by elements of the far-left. Bernie Sanders, for one, represented the anti-Israel sentiments of the far-left by refusing to so much as attend the mega-conference held by AIPAC in 2016.

On the center-left, too, AIPAC would endure increasing isolation. During the president’s pursuit of a disastrous nuclear agreement in Iran, AIPAC valiantly took the administration head-on, swarming the capital with agents tasked with explaining the dangers of the agreement. In these moments, AIPAC proved not only its fierce commitment to ensuring Israel’s security, but more importantly, its willingness to risk its most precious relationships on her behalf. Though the effort failed to prevent Obama from signing an embarrassing agreement with the Iranian regime, it still represented AIPAC at its best: totally bipartisan, yet willing to take on a side when Israel’s security concerns demanded that it do so.

Indeed, AIPAC’s efforts harmed some of the lifeblood of its access and influence. Democratic leaders openly condemned AIPAC for abandoning its bipartisan principles in its fierce opposition of Obama’s principal foreign-policy objective. The Obama administration would offer a significant boon to AIPAC’s chief competitor on the left, Jeremy Ben-Ami’s J Street, which seemed founded on a singular policy of criticizing Israel.

In March of 2015, at the height of his campaign to sign a deal with Iran, President Obama sent his chief of staff Dennis McDonough to headline J Street’s annual conference. Just a few years earlier, in 2008, J Street operated as a four-man team that had only recently graduated from Ben-Ami’s basement. By 2015, due in no small part to increasing support from the Obama administration, J Street had grown to encompass more than 60 employees, with 160,000 paying members, 3,000 of whom be there to hear the top staffer at the lobby’s annual congress.

All of this influence, however, would be used not to advance a pro-Israel agenda, but a pro-Obama one.

During the push for the Iran deal, J Street would receive an astounding $576,500 from the Ploughshares Fund—the equivalent of nearly one-third of the lobby’s entire 2014 budget—to help the Obama administration sow the seeds a deal that almost every Israeli political figure warned would permanently undermine their state’s security. Following numerous meetings between Ben-Ami and White House officials, the organization created a website, IranDealFacts.com, a digital echo-chamber of the administration’s Iran deal talking points.

Ultimately, all of these developments represent both a tragic turn for the American pro-Israel community.

Unlike J Street and the ZOA, which have in no uncertain terms cast their political allegiances with a single side, AIPAC is a distinctly bipartisan organization. Every single bill supported by the lobby must have both Republican and Democratic co-signers, and at all of AIPAC’s various forums, both arch-rivals and ardent supporters of the current administration will receive equal time to speak their minds from the podium.

Even as some see bipartisanship as a “relic,”  the fact is that it has never been more critical.

After all, once a lobby retreats to one side of the political aisle, their allegiances lie less in policy objectives then in towing political lines. J Street, therefore, will flatter those in Obama’s State Department, despite overwhelming opposition from the Israeli people they’re claiming to protect. Differently, the ZOA found itself mired earlier this year in a scandal involving the nation of Qatar, something a strictly bipartisan and democratically led organization like AIPAC would never have gotten involved with.

There are, thank God, many pro-Israel organizations. And as active as they may be, they all need AIPAC because of its across-the-board legitimacy as a lobby group defined only by its commitment to Israel, without any allegiances to either side of the political spectrum.

As an activist who spent his formative years as rabbi to the students of Oxford University, I can see how tragic it is when one party (the Conservatives) becomes the pro-Israel party while Labor is run by an out-and-out anti-Semite. Such partisan support for Israel by only one side of the aisle would be an American tragedy.

Rabbi Shmuley Boteach is an American Orthodox Jewish rabbi, author, TV host and public speaker.