Since they do not give the exact methodology, it is hard to go into detail on the bias inherent in the poll, but one question they show in full:
Professional pollsters know that the order of the choices can influence results. The wording here shows that they always presented their own preference first for this question, and the "other" side last.
Since the poll shows pretty convincingly that most American Jews do not follow Israel closely, it means that the interviewees are especially prone to manipulation since they do not have strong views on the topic.
In this case, J-Street first presents a statement that sounds reasonable to an little-informed subject:
Some Jewish organizations in the United States say that America has a special relationship with Israel and we must support our democratic ally, but this latest incident that took place during Vice President Biden's visit to Israel was an insult to America and damages our interests in a region where we are fighting two wars. The relationship between the United States and Israel must be a two-way street that allows an honest public discussion, and even criticism, when our two countries disagree.A person without strong opinions will hear that statement and will generally agree as it sounds reasonable. The question itself is a form of education for the person polled.
Then, J-Street talks about "others," meaning people who do not agree with the already established reasonable statement:
Other Jewish organizations in the United States say that Israel is America's closest ally in the Middle East, and the Obama Administration's recent statements regarding the U.S. relationship with Israel are a matter of serious concern. The Obama Administration should work closely with Israel in a manner befitting strategic allies, make a conscious effort to move away from public demands and unilateral deadlines directed at Israel, and take immediate steps to defuse tension with the Jewish state.Now that the subject already has committed himself to the first statement, he will be reticent to change his mind so quickly when hearing the second, "other" statement.
I can guarantee you that if the two questions were reversed, switching "some" with "others," the results would be reversed as well.
It is also telling that J-Street doesn't bother finding out what Jews who are care the most about Israel feel. They rely on the ignorant, apathetic Jewish majority for their support. Which means that they rely on Jews they can manipulate.