The Israel Project, which includes 20 members of Congress on its advisory board, issued a confidential report in January outlining how supporters can influence US public opinion during the new Obama term.
Marked "not for distribution or publication," the document tells activists that anyone who opposes settlement expansion on Palestinian land should be told they are supporting "ethnic cleansing to remove all Jews".
The revelation comes as Israeli PM Benjamin Netanyahu prepares to meet with US diplomats in London for a new wave of peace talks.
President Obama has made it a cornerstone of his foreign policy agenda that Israel must halt expansion of settlements on the West Bank and Gaza before efforts to broker a deal with the Palestinians can progress.
He told Mr Netanyahu in May that "settlements have to be stopped in order for us to move forward" – a request that the PM nimbly side-stepped by vowing to halt new construction but allow "natural growth" of existing outposts.
There are currently 500,000 Israelis living in more than 100 settlements that have been built on Palestinian land since 1967.
Successive Western governments have warned Israel that the settlements – illegal under international law – are a major obstacle to peace. But with hardline religious groups claiming biblical rights to all of Greater Israel, progress on dismantling them has been painstakingly slow.
Underscoring the gravity with which some Jews view the subject, The Guardian has now obtained copies of a memo in which members of The Israel Project give step-by-step guidelines for manipulating US public opinion.
Responding to President Obama's call for a halt to settlement expansion, the report states: "The idea that anywhere that you have Palestinians there can't be Jews - that some areas have to be Jew-free - is a racist idea.
"We don't say that we have to cleanse out Arabs from Israel," it reassures US-based activists. "They are citizens of Israel. They enjoy equal rights. We cannot see why it is that peace requires that any Palestinian area would require a kind of ethnic cleansing to remove all Jews."
This approach, supporters are told, is "the best settlement argument" for winning over would-be dissenters such as President Obama.
What's more, in a remarkably duplicitous admission, the leaked document goes on to warn activists that they should downplay any suggestion that religious motivation underpins their support for the settlements.
"You must avoid using Israel's religious claims to land as a reason why Israel should not give up land," it admonishes. "Such claims only make Israel look extremist to people who are not religious Christians or Jews."
The damaging report comes on the heels of a comparable outrage closer to home, in which Fox News commentator Glenn Beck enraged public opinion by calling President Obama a "racist" with a "deep-seated hatred for white people" – prompting 33 Fox advertisers to pull the plug on his show.
Mr Beck will return to work at the news station tomorrow after taking a hastily-arranged vacation. He was not disciplined for the outburst.