The left-wing J Street lobby has failed to gain much traction on Capitol Hill in its four years of existence. So it was hardly surprising that it would attempt to gain some publicity on the eve of the annual conference of AIPAC, the organization it once hoped to supplant. The group released a memo by its pollster Jim Gerstein that, it claims, debunks the notion that President Obama is in any danger of losing his stranglehold on the Jewish vote this fall.

Gerstein’s numbers and analysis are, however, merely a rehashing of much of what we already knew about the Jewish vote. It also largely mischaracterizes the debate about the issue. No one is disputing that Obama or any Democrat with a pulse will get a majority of Jewish votes in 2012. But neither is there much doubt that there is much chance that he will not get the same 78 percent of Jewish support that he got in 2008. The question is, after three years of distancing himself from Israel and engaging in disputes with the Jewish state, how big will be the drop off this year? The jury is obviously still out on that, but Gerstein’s assumption that it will not be much seems unfounded. Equally unreliable, as well as telling, is his argument that few Jews vote on the basis of U.S. policy toward Israel. Given the all-out charm offensive that the Obama administration has been directing toward Jewish voters in the last few months — which will reach another crescendo today as President Obama addresses the AIPAC Conference — it would seem the White House has a different view of the question than its J Street idolaters.

One of the main fallacies in Gerstein’s memo seems to be his assertion that the Republicans are unlikely to do better in 2012 with Jewish voters than they did in their 2010 midterm landslide. Gerstein rightly says that the Democrats held most of the Jewish vote in 2010 even as they were getting slaughtered nationally. But the 2010 ballot was largely a referendum on Obama’s domestic policies like ObamaCare that were far more popular among Jews than among the general population. The presidential vote this year will provide pro-Israel Jewish moderates and Democrats an opportunity to register their dismay at Obama’s attitude toward Israel prior to his re-election campaign. Though he attempts to ignore data that contradicts his predictions, such as the Pew Research Study that showed a dramatic decline in Jewish affiliation toward the Democrats in the last four years, the administration’s obvious concern about the Jewish vote this year belies Gerstein’s false optimism on this score.

Gerstein is right when he says that Democrats retain the almost blind loyalty of a majority of American Jews. As I write in my feature in the March issue of COMMENTARY, “Jews, Money and 2012,” there is virtually nothing Obama could do or say in the next eight months that would cause him to get less than 50-60 percent of the Jewish vote. But the difference between that base line and the 78 percent he got in 2008 is very much up for grabs. Though those numbers may not be enormous, contrary to Gerstein’s argument, they are enough to make a difference in a number of crucial states such as Florida and Pennsylvania.

President Obama’s fortunes are on the upswing due to slightly better economic numbers and the fallout from a bitter Republican primary battle. But it’s a long way to November, and the standoff with Iran and the president’s willingness to back up his talk on the nuclear question with action, will have a major impact on the Jewish vote this year. The potential for a significant drop off from Obama’s 78 percent — especially if the GOP nominates a candidate not identified with the Christian right — is something that more realistic Democratic sources than J Street and Gerstein are right to take very seriously.