For more than half a century, the American Israel Public Affairs Committee (Aipac) has been the premier pro-Israel lobbying group in the US. Since its inception in 1951, Aipac has been instrumental in shaping American foreign policy to promote the Israeli position on the Middle East conflict and other world issues. Once a small organisation with a handful of staff, Aipac grew substantially during the Ronald Reagan presidency and afterward, and today has more than 100,000 members. Aipac, which now lobbies both the executive and legislative branches of the US government, proudly states on its website that it conducts more than 2,000 interviews with members of Congress each year, resulting in about 100 pro-Israel policy decisions.

Although Aipac has long held primacy among American foreign policy lobbying groups, there are several other American Jewish organisations that oppose Aipac, accusing the group of pushing a right-wing agenda that does not truly reflect the opinions and values of American Jews. Prominent among these organisations is the Israel Policy Forum, founded in 1993 to lobby American lawmakers in support of a two-state solution to the Palestinian-Israeli conflict. In 2008, Jeremy Ben Ami, a former adviser to president Bill Clinton, founded J Street, a left-leaning Jewish lobbying group that describes itself as pro-Israel and pro-peace. Ben Ami says that J Street, which supports the two-state solution to the Middle East conflict, reflects the opinions of American Jews today more accurately than Aipac's hard line. According to Ben Ami, US policy has for years been heavily influenced by the Israeli right wing, which J Street believes has not served the strategic interests of the US or Israel. For American policy makers, he adds, the genuinely pro-Israel choice is to help realise a two-state solution and a comprehensive peace between Israel and its neighbours.

Aipac's influence is also waning in the sphere of public opinion, as Americans have begun to question whether its influence is serving the interests of the US. This shift has come on the heels of several recent events that have prompted Americans - particularly Jewish Americans - to rethink their blind loyalty to the state of Israel. The first of these wake-up calls came with the publication of John Mearsheimer and Steven Walt's 2006 paper The Israel Lobby, which argued that the extreme influence that groups like Aipac have held over US policy makers has caused the US to adopt positions detrimental to its own national interests. Mearsheimer and Walt were instantly dragged over the coals for their paper, with Aipac leading the charge in calling them anti-Semites, conspiracy theorists, and failed academics. This backlash ultimately served to enhance the work's publicity and credence, while helping to motivate its expansion into a book, The Israel Lobby and US Foreign Policy.

The second paradigm-shifting event came during the Israeli bombardment of Gaza in December and January. The Gaza war caused Israel to lose a great deal of sympathy and credibility around the world. By targeting schools, hospitals and mosques in a disproportionate war pitting the most sophisticated military technology against small militias, Israel ruined what remained of its image as the underdog in a David-and-Goliath battle, as well as its long-touted moral high ground. While most of the world, including many Americans and Jews, looked with revulsion upon Israel's actions during Operation Cast Lead, Aipac supported the operation wholeheartedly, at some cost to its reputation.

Finally, Aipac's role in the Charles W. Freeman affair of 2009 illuminated the extent of its influence and the paranoid vehemence with which it attacks those who dare to question American support for Israel. Freeman, chosen by Obama to chair the National Intelligence Council, was forced to resign his position after fierce attacks from Aipac, which objected to his belief that unconditional support by the US for Israel's self-defeating policies was damaging prospects for peace in the region. Freeman fought back against his critics, however, calling them "unscrupulous people with a passionate attachment to the views of a political faction in a foreign country", whose aim is "to prevent any view other than its own from being aired". "There is," he continued, "a special irony in having been accused of improper regard for the opinions of foreign governments and societies by a group so clearly intent on enforcing adherence to the policies of a foreign government".

Freeman's outspoken self-defence is notable. In the past, it was nearly impossible for Western and particularly American public figures to openly challenge the pro-Israel point of view.

With the shifting image of the Israeli lobby in the eye of the American public, Aipac's membership, donations and influence are likely to decline, and more balanced and pragmatic approaches to the Palestinian-Israeli conflict are likely to appear in American policy circles. Additionally, the current American leadership appears much more open to new strategies in Middle East than previous governments. Between the shifting perceptions of the American public and the president's attempts to strike a balanced posture, Aipac's sole domination of the American discourse on Israel and the Middle East may be coming to an end.

Dr As'ad Abdul Rahman is chairman of the Palestinian Encyclopedia.