The 50 members of the board of directors are a cross section of influential figures in Republican and Democratic politics and in civic affairs across the country. They include Steven Grossman, former chairman of the Democratic National Committee, and former senator Rudy Boschwitz (R-Minn.), a major Bush fundraiser. Norman Brownstein, a prominent Denver lawyer, was an early financial backer of the Kerry campaign.
Since 2000, the board members have contributed an average of $72,000 each to campaigns and political committees. One in every five AIPAC board members is a top fundraiser for Kerry or Bush.
The federal investigation itself has produced the most recent demonstration of AIPAC's power and standing, in the outpouring of support for the organization from U.S. officials that began hours after news of the federal inquiry broke.
"I know AIPAC; I know the AIPAC leadership. It is an outstanding organization," said Senate Majority Leader Bill Frist (R-Tenn.). Senate Minority Leader Thomas A. Daschle (D-S.D.) declared, "America is better and stronger for" AIPAC.
Two days after the first news reports, Republican politicians -- normally wary of controversy -- turned out in force at an AIPAC-sponsored event outside the GOP convention in New York. By AIPAC's count, the attendees included more than 60 House members, eight senators, five governors, two Bush Cabinet members and Bush campaign manager Ken Mehlman.
Through more than 2,000 meetings with members of Congress, AIPAC activists help pass more than 100 pro-Israel legislative initiatives a year. On its Web site, AIPAC lists priorities including legislation to curb Iran's nuclear program; procuring nearly $3 billion in aid for Israel; and funding U.S.-Israeli efforts to build a defense against unconventional weapons.
AIPAC does not have a political action committee and does not endorse candidates. But it is widely viewed by friends and foes as wielding significant political power.
In 2002, two Democrats in Congress with records of voting against Israel's interests -- Reps. Earl Hilliard of Alabama and Cynthia McKinney of Georgia -- faced primary opponents who received substantial support from Jewish donors. A majority of AIPAC board members gave to either McKinney's challenger or Hilliard's or both. Hilliard and McKinney lost. Bill Banks, McKinney's campaign manger, charged that AIPAC had made her the "No. 1 candidate to try to remove from office." AIPAC denied the accusation.
Even some Israeli officials have said they are uncomfortable with AIPAC's influence in U.S. politics.
"They have the threat of voting out [congressional] representatives," said Yossi Beilin, a Cabinet minister under former Labor Party prime minister Ehud Barak. "I never liked this leverage they have. It's counterproductive. Some see AIPAC as the long arm of Israel, even if it's totally wrong."
Over the years, AIPAC has accumulated many critics, including angry competitors, who feel their voices on Middle East policy have been subordinated to the policy positions taken by AIPAC.
Rep. David R. Obey (Wis.), the ranking Democrat on the House Appropriations Committee and a supporter of the policies of the more dovish Labor Party in Israel, contends that AIPAC has "pushed the Likud Party line and in the process has crowded out other voices in the Jewish community," especially those pressing for withdrawal from West Bank settlements as a concession in the peace process.
Some Israeli politicians also accuse AIPAC of representing the more hawkish factions within the Israeli government.
"They had their own agenda," said Beilin, a longtime participant in Israeli-Palestinian peace efforts. "They contradicted our government. When there was a unity government, they would say, 'But you only represent Labor,' even if I was representing the prime minister."
While many Israeli and AIPAC supporters have said it is unnecessary for Israel to engage in espionage inside the United States because of the close relationship between the Bush and Sharon administrations, some officials and observers argue that Israel has a strong interest in collecting information that could help it influence U.S. policy on Iran, which Israeli officials say is their country's greatest enemy. Both the United States and Israel have advocated strong stands against Iran's development of nuclear weapons, but Israel has urged more aggressive action than Washington. The Pentagon's Franklin, who officials said is cooperating with authorities, is suspected of sharing a document concerning the debate within the Bush administration over policy on Iran.
Ifraim Sneh, a Labor Party member of the Israeli parliament and former Cabinet member, said he has met with AIPAC members in informational exchanges for years.
"When I tell AIPAC people what the situation is here, and they tell me what the situation is in Washington, I think it's legitimate," Sneh said. "There's nothing wrong with it. It's normal. Washington is a town where the number one commodity is political gossip and political information."
Researcher Lucy Shackelford contributed to this report. Moore reported from Jerusalem.