When Sen. Joe Lieberman, I/D-Conn., walked into the annual dinner of the American Israel Public Affairs Committee last week, he began almost immediately to hold court among his many admirers. "Our table was swamped all night," said Lonnie Kaplan, Lieberman's host and a former AIPAC president. "To get him to the table was a major effort."
While Lieberman's national stature has faded since he became the first Jew to run on a major party ticket for vice president in 2000, he remains akin to a rock star in the American Jewish world, especially among national security hawks. But now, the former Democrat -- who became an independent in 2006 after losing his party's nomination for re-election to the Senate in Connecticut -- is raising eyebrows among some of his biggest fans.
Lieberman surprised many in December when he endorsed Republican John McCain for president, but others dismissed it as just another step in Lieberman's march to the right, spurred by a mix of support for the Iraq war and frustration with Democrats who did not support him after his primary loss. The real confusion, however, has come in recent weeks, as Lieberman has gone on the offensive against Democratic candidate Barack Obama, suggesting he is "naive" on U.S. policy toward Iran and its president, Mahmoud Ahmadinejad.
"If... anybody thinks you can go over there and sort of talk reason, and hug and kiss Ahmadinejad, and he's... just going to act better, that's just naive," Lieberman told FOX News on May 20. "It's very naive of Senator Obama."
After Obama spoke to AIPAC last week, Lieberman participated in a McCain campaign conference call with reporters, where he said Obama was blaming American foreign policy for the current situation in Iran.
His comments play into hesitation some Jews already have about Obama's commitment to Israel and his policies toward Iran, raising hope in Republican circles that McCain can garner more American Jewish support than the 25 percent President Bush won in 2004.
"Lieberman can certainly help with those who are teetering and normally vote Democratic but have some concerns or questions" about Obama, said Jay Footlik, who served as Lieberman's liaison to the Jewish community in his 2004 presidential bid and later played the same role for Sen. John Kerry, D-Mass.
While Jews largely back Democrats on social issues, support for Israel often serves as a litmus test for candidates. Obama is seen by some as vulnerable and inexperienced on the Middle East, and McCain's relatively moderate social positions could push more Jews to the right. Lieberman knows the issues and code words that can strike fear in many Jewish voters.
"I do believe that generally Republicans like to put support of Israel as the issue to divide the Jewish community, and Democrats try to take it off the table," said Kaplan, a Democratic fundraiser who has backed pro-Israel Republicans. "Both sides will try to do that this time."
Several American Jewish leaders said they were concerned about Lieberman actively campaigning against Obama. While they said they expected Lieberman to tout McCain's perceived virtues on the Middle East and other issues the community cares about, they didn't anticipate that he would directly criticize the presumed Democratic nominee.
"I'm a bit surprised and disappointed that Joe has gone this negative," said one Jewish political operative, who spoke on condition of anonymity. "I didn't think it was in his character."
Lieberman's office declined requests for comment.
The Connecticut senator has taken other shots at Obama's Middle East policy positions. He wrote in the Wall Street Journal last month that Obama has proposed a "blanket policy of meeting personally as president, without preconditions, in his first year in office, with the leaders of the most vicious, anti-American regimes on the planet."
He also praised Bush for his remarks in Israel last month, in which the president chastised leaders who would negotiate with "terrorists and radicals," calling such moves the "false comfort of appeasement." Many took the president's comments as a direct attack on Obama.
"My impression is that Jewish Democrats, even the solid pro-Israel Democrats, are pissed off with" Lieberman, said Ron Kampeas, Washington bureau chief for JTA, a wire service for Jewish newspapers.
Lieberman could be filling a void in the Jewish Republican world. There are few prominent Jewish Republicans in office, and even fewer with the national spotlight Lieberman enjoys. It is unlikely that Sen. Norm Coleman, R-Minn., who faces a tough re-election challenge this year, or Sen. Arlen Specter, R-Pa., who is battling cancer, will campaign for McCain as much as Lieberman will. And there is only one Jewish Republican in the House, Rep. Eric Cantor, R-Va.
Having Lieberman on the trail for McCain could sway undecided Jewish voters, especially in places like the swing state of Florida. Lieberman has the potential to play the same role former New York City Mayor Ed Koch did when he endorsed Bush in 2004 over his party's nominee.
"I think he'll have more influence," Koch said. "His name is more well known than mine, and his involvement in the Senate on so many issues makes him a much more effective speaker than myself."
Koch spoke to Jewish groups on Bush's behalf throughout 2004, focusing primarily on New York transplants in Southern Florida and senior citizens. He joked that during that time, he often needed to remind voters they were not voting against Franklin Roosevelt by choosing a Republican.
Koch said his influence -- which the Bush administration praised for helping push them over the top in Florida -- came from being an independent voice respected by American Jews. Lieberman could have the same effect.
"I think that his endorsement, whatever endorsement he makes on any issue, is highly regarded, especially in the Jewish community," Koch said.
But others suggest Lieberman's name has been sullied by his embrace of McCain. To these observers, Lieberman has lost much of the heroic stature he once enjoyed, along with the sympathy he garnered after losing the presidential race in 2000, the presidential primary in 2004 and his Senate primary in 2006.
"I know, among the Democrats, he's completely lost credibility for leaving the party," Kampeas said. "He actually had sympathy after 2006, but in embracing McCain, he has really pissed off a lot of Democrats."
Jewish Democrats say they will showcase other Jewish senators who are actively backing Obama and perhaps paint Lieberman as a Republican in Democratic clothing. But it may be hard to attack someone who once held their highest esteem.
"I have great respect for him," Footlik said. "I just disagree with him on this."