Senator Chuck Schumer and Congressman Eliot Engel are both prominent members of New York's Democratic Congressional delegation. They also have just announced they will vote against President Obama's Iran deal.

That opposition could jeopardize Schumer's political ambitions, said Charles Sennott, head of The GroundTruth Project.

"I do think if he wants to become the leader of the Senate—which we know he does—for the Democratic Party, he's walked a pretty perilous line in terms of questioning the president this intensely on something that is that important to the President of the United States," Sennott said.

But a much larger issue looms behind the immediate political ramifications of supporting the agreement, Sennott said, and that's the role of lobbying organizations in the political process. The pro-Israel lobbying organization AIPAC reportedly sent 60 activists to Senator Schumer's office and has spent $20 million dollars to oppose the deal

"It's absolutely the third rail of American politics, because it's about the influence of AIPAC and other lobbies on American foreign policy," Sennott said.  

To hear more from Charles Sennott—including his take on how the Iran deal is splitting the pro-Israel lobby in Washington—tune in to Boston Public Radio above.