J Street, likely to emerge after the 2016 election as a major force within the Democratic Party, is expecting from Senator Chuck Schumer to fall in line with supporters of the Iranian nuclear deal once he assumes leadership of the Democratic Caucus in the U.S. Senate.

“Senator Schumer understands that he’s very much in the minority in his own party and he would have a strong uphill battle were he to try to do anything that would actually undermine the deal,” J Street President Jeremy Ben-Ami told Jewish Insider on Wednesday.

“In the final vote, there were only four Democratic senators who did not vote to support the deal,” he asserted. “Senator Schumer did not work hard to rally opposition. He stated his personal view on this and he voted against it, but he was also very understanding and realistic that 90 percent of his colleagues in the Democratic caucus were in favor of the deal; sided with the president, with Secretary [Hillary] Clinton] and Senator [Tim] Kaine.”

In a recent speech at the Israeli American Council National Conference in DC, Schumer called on Congress to immediately extend the Iran Sanctions Act and keep Iran’s feet to the fire. “As you know, I voted against the Iran deal and I have never regretted that vote a single day since,” Schumer said to loud applause.

Schumer is one of seven Democrats who signed a letter to Senator Mitch McConnell asking that he “prioritize” a clean extension of the Iran Sanctions Act during the Senate’s end-of-year session. The extension, as proposed by the senior Democrats, would run through 2026. “It is essential that Congress keep Iran’s feet to the fire to make sure they do not violate the JCPOA. This bill would provide the sanction authority that helps us do just that,” Schumer said in July.

According to Ben-Ami, the reauthorization of the Iran Sanctions Act for ten years is something J Street can live with. “It is not viewed by us as a step to undermine the deal,” he said. “That in and of itself is not evidence of an intent on part of the senator to use his potential position (as Senate Majority Leader) in a way that might undermine the deal, in the years going forward.”

On Wednesday, J Street kicked off a national campaign to bolster Senate candidates who support the Iran nuclear deal with a $500,000 television ad buy in Pennsylvania and Wisconsin, two races that are in reach or viewed as toss-ups.

“We’re aiming to fundamentally transform the political calculation by demonstrating that the Iran nuclear agreement and diplomacy-first approaches make for good policy and for good politics,” Ben-Ami said in a conference call with reporters. “We aim to exact a cost from the deal’s most strident opponents, who tried at every turn to undercut the very negotiations that led to the historic defanging of Iran’s nuclear weapons program.”

J Street ran a $5.5M campaign last year in support of the deal in Congress, which included targeted television, print, and digital ads in key media markets around the country.

J Street’s political arm is supporting candidates in over 100 local races across the country. J Street’s national political director Ben Shnider told Jewish Insider earlier this year that the group has decided to seize the opportunity to expand its control and influence within the Democratic Party after scoring a victory on the Iran deal. “We see this as a unique opportunity to go on the offense and prove that standing up for a diplomacy first approach – which has been proven to be in the best interest of the U.S. and Israel – is not just smart policy but also savvy politics,” Shnider emphasized.

The pro-peace group was recognized by President Obama and Vice President Joe Biden for its lobbying and successful campaign in support of the nuclear deal last year. “You deserve great credit for the [Iran deal],” Biden said in a speech at the annual J Street gala in April. “Your organization played a critical role in mustering the support at home to get that deal through the United States Congress… “Thank you, thank you, thank you for your effort. You have made the world a little bit safer.”

Promising to expand the national campaign if needed, Ben-Ami stressed, “For us, this political fight represents the second chapter in the struggle to uphold the Iran nuclear agreement—and one that is every bit as important as the initial policy win. We need now to put candidates in office not only to defend against ongoing efforts to sink the deal in Congress, but also to protect the important precedent its passage set for pro-diplomacy-first policies going forward.”