Chuck Schumer’s decision to oppose the Iran Deal is causing some fear among deal supporters that he has broken down the Democratic Party firewall of support for the deal by giving American Jews who are fencesitters an excuse to come out against it.

Indeed, the rightwing site Breitbart has a poll, conducted before Schumer’s announcement, saying that Jews are changing their minds and swinging against the deal. And Bill Kristol of the Emergency Committee for Israel says: “Administration wanted Schumer to wait till the end if he was going to be against deal. His announcing now opens a path to 67 (& 290) votes [against the deal].”

From the start, I have focused on the extent to which the politics of the deal are an inside-Jewish game. The White House has at times treated the matter as such, with special and lengthy briefings for Jewish leaders and politicians. “White House begs to send its top officials to brief 700 Aipac activists,” Laura Rozen writes, underlining that dynamic. And two of the three officials the White House sent to that meeting, Wendy Sherman and Adam Szubin, “who also happened to be two of the key negotiators, are Jewish,” writes Ilan Goldenberg, a former Obama official who is Jewish and has been an outspoken advocate for the agreement. Of course, the fact they’re Jewish is not just a coincidence. Pro-Israel Jews are just that important in the power structure and Middle East policymaking.

Today Jeremy Ben-Ami of the liberal Zionist group J Street, which is working overtime for Obama on the deal, tried to hold the line on Jewish support. Here is a portion of his email, emphasizing the large numbers of Jewish backers of the deal.

I know Senator Schumer’s decision is causing concern among the deal’s supporters. But recognize this: the growing coalition in support of the agreement is impressive in quality and depth… Florida’s Bill Nelson and New York’s Kirsten Gillibrand — who between them represent almost 2.5 million Jewish Americans in Congress — both came out this week courageously arguing that the agreement is the best option to stop the Iranian nuclear program and safeguard American and Israeli security. And several Jewish and staunchly pro-Israel members are among the most outspoken advocates for the deal, including Congress’s senior Jewish voice, Rep. Sander Levin, and the Ranking Democrat on the House Intelligence Committee California’s Adam Schiff….

Notice that some of J Street’s appeal involves bolstering Israeli militants:

Throughout the Congressional recess, J Street will continue our multi-million dollar ad campaign to educate and inform undecided Americans and Members of Congress about the merits of the deal. And, critically, we’ll bring veteran Israeli national security leaders to the States to explain why this deal is by far the best option for the US and for Israel.

Make no mistake, some of these security leaders are likely war criminals. They are a necessary part of the pro-deal’s lobby, given the constitution of the power structure. Jim Fallows and David Bromwich (neither of whom is a Zionist) touts their support. But when the deal goes through, its significance in American politics and Jewish politics, is that the neoconservatives will be routed. J Street will gain immeasurable prestige politically; the Israel lobby will be reconstituted as a liberal Zionist lobby. Bill Kristol will have to get some other sales job.

But non-Zionist, pro-boycott organizations have also worked hard for this deal, notably Jewish Voice for Peace. The rejection of rightwing Zionism/neoconservatism will open the next chapter in the Jewish ideological debate over Israel. BDS– boycott, divestment, and sanctions– will be openly debated in the 2016 election campaign.