Almost 80 per cent of Jewish Americans cast their ballot for Barack Obama in 2008. Blacks were the only racial, ethnic or religious group to vote more en masse for the first African-American presidential nominee.
Now, an upset victory by Republican candidate Bob Turner in a heavily Jewish New York City district – the first GOP win there since 1923 – has reignited speculation that unhappiness with Mr. Obama's policy toward Israel could cost Democrats critical support among Jews in 2012.
The prospect of Mr. Obama becoming another Jimmy Carter – the only Democratic presidential candidate since 1920 to win less than 50 per cent of the Jewish vote – seems far-fetched. But even modest slippage in support among Jews could put some districts, and swing states like Florida, in the GOP column.
It would be precipitous to draw sweeping conclusions from the results of Monday's special election. It was held to fill the seat vacated in June by Anthony Weiner, a Democrat downed in a sexting scandal.
Low turnout, a dismal economy and opposition to a gay-marriage law recently enacted by the state's Democratic legislature were certainly factors in the decision by voters in New York's 9th District to send a Republican to Congress for the first time in 88 years.
Still, high-profile Jewish political and religious leaders, including the city's former Democratic mayor, Ed Koch, endorsed Republican Mr. Turner explicitly to express their discontent with Mr. Obama's Israel policy. The issue figured as prominently as the economy in the campaign.
Democrats tried to play down the role Mr. Obama's Middle Eastern policies played in the election, but as Michael Powell, who writes the Gotham Extra blog at The New York Times, wrote of a Turner rally: "You could watch a crowd that mixed old Irish and Italians with many Orthodox and Hasidic Jews applaud as [Mr. Koch]and Assemblyman Dov Hikind, a power broker within the Brooklyn-Queens Orthodox population, talked about Israel, Israel and Israel, and President Obama's alleged disregard for the same."
Substantively, Mr. Obama's positions regarding Israel and negotiations toward a Palestinian state are not very different from those espoused by George W. Bush. But his unwillingness to couch them in the traditionally pro-Israel rhetoric of previous administrations has made him an object of suspicion in the eyes of the powerful American Jewish lobby.
Relations between the White House and Israeli Prime Minister Benjamin Netanyahu's Likud-led coalition have been cool since Day 1. They only got cooler after Mr. Obama insisted in a May speech that "the borders of Israel and Palestine should be based on the 1967 lines with mutually agreed swaps." The 1967 lines refer to the borders that existed before the Six-Day War led to Israeli occupation of the West Bank and Gaza.
In an address a few days later, before the hawkish American Israel Public Affairs Committee, Mr. Obama said that his position had been broadly "misrepresented." Indeed, most of his critics had ignored the "mutually agreed swaps" clause, making it look like Mr. Obama was calling for a massive surrender of existing territory by Israel that would leave it more vulnerable to attack from hostile neighbours.
Yet, Mr. Obama's trust deficit with American Jewish leaders (if not voters) stems less from his policies toward Israel than his attitudes toward it. He has never delivered the kind of full-throated endorsements of Israeli exceptionalism that American Jews have come to expect from a President.
Part of this stems from Mr. Obama's mission to repair America's standing in the Muslim world. But it also stems from his belief that the traditional pro-Israel U.S. position has not advanced peace in the region.
Signs of Jewish discontent were evident before Mr. Obama's election. In an early 2008 speech, he took aim at the U.S. Jewish lobby, saying: "There is a strain within the pro-Israel community that says unless you adopt an unwavering pro-Likud approach to Israel that you're anti-Israel."
Four months before the 2008 vote, a Gallup poll pegged Mr. Obama's support among Jewish voters at only 61 per cent – low by Democratic standards.
Jonathan Sarna, a professor of American Jewish history at Brandeis University, figures John McCain's selection of Sarah Palin is what ultimately drove 78 per cent of Jews to embrace Mr. Obama on election day. But Mr. Obama may have misread his mandate from them.
"A lot of his aides supported a much more dovish policy," Prof. Sarna said in an interview. "I think he thought there was a silent majority of American Jews who agreed. I'm not so sure that's turning out so well for the President."
Any exodus of Jewish voters from the Democratic fold in 2012 would likely show up most in Pennsylvania and Florida, swing states that Mr. Obama needs to win to hold on to the White House.
Jewish voters, disproportionately seniors, account for about 8 per cent of people who turn out to vote in Florida, according to University of Miami ethnic geographer Ira Sheskin. But he is skeptical they will imitate Jewish voters in New York's 9th District.
"The Republican Jewish coalition has for years been trying to tell people that the percentage of Jewish Republicans is increasing," he said in an interview. "I can't find any evidence of that in my data."
Does that make New York's 9th an aberration? Or is it one more big reason for the White House to worry about 2012?