This impressive turnout by lawmakers is a point of pride for AIPAC, which boasts on a fact sheet that the event will draw more Members of Congress than almost any other event except for a joint session of Congress or the State of the Union.
It is the place to be in the pro-Israel community. Much schmoozing will transpire, said William Daroff, vice president for public policy and director of the Washington, D.C., office of the Jewish Federations of North America.
The three-day conference, which includes a lobbying day on Tuesday that involves 500 meetings on Capitol Hill, will once again give the organization a chance to flex its political muscle.
But the gathering is also coming at a time of increasing challenges for the organization, the most recent being the rising tensions between the Obama administration and the Israeli government over proposed Jewish housing settlements in East Jerusalem. Administration officials publicly chastised Netanyahu for the housing announcement while Vice President Joseph Biden was in Israel trying to further the peace process.
AIPAC responded with a statement calling on the White House to defuse the tension with the Jewish state and move away from public demands and unilateral deadlines directed at Israel.
Once regarded as the authoritative voice among American Jewry on Israeli matters, AIPAC now finds itself competing with other voices in the Jewish community regarding Middle East issues.
J Street, which was founded two years ago to provide an alternative, more liberal stance on the peace process, issued a statement supporting the administrations stand on the Jewish housing settlements. J Street Executive Director Jeremy Ben-Ami called the administrations tough language both understandable and appropriate.
The tempest also comes as AIPAC is finally recovering from an embarrassing episode that occurred five years ago when two of its officials were charged with improperly providing national security information to journalists and Israeli diplomats. Last year, the Justice Department withdrew the charges against the men, who had been dismissed by AIPAC in 2004.
AIPACs critics and competitors say the organization still wields enormous clout on Capitol Hill. Last year, it spent $2.7 million on federal lobbying with a government affairs staff of nine led by Marvin Feuer, a former Pentagon official, and Bradley Gordon, who had worked for House Foreign Affairs Chairman Howard Berman (D-Calif.).
But outsiders also say that AIPACs influence is not as great as it has been in the past, when lawmakers feared that crossing the organization would be politically ruinous.
They still have many Members genuflecting. But I think in some ways the reality has changed, said James Zogby, the president of the Arab American Institute, which has supported Obamas opposition to the growth in Jewish settlements.