By the time you read this, the bloggy fringes of the Democratic Party will already be inveighing against Speaker Pelosi and Majority Leader Reid. Both leaders will have just given speeches on the Middle East to the American Israel Public Affairs Committee.

Aipac, the establishment pro-Israel lobby, in this day and age is a liability to Democratic leaders who want to please the online activists that might be called the credulosphere. For the credulosphere, Aipac has become something like what the Trilateral Commission was a generation before for fringe anti-communists.

It’s not just that Aipac musters towering majorities in Congress for resolutions favoring Israel or the annual foreign aid budget. For the willing believers inside the netroots, Aipac foisted the Iraq war on the world with connivance of the Bush-Cheney war machine. That was the thesis published last year by two professors, University of Chicago’s John Mearsheimer and Harvard’s John F. Kennedy School of Government’s Stephen Walt, and it has been echoed by a gullible and self righteous lot that warns their Internet readers of the latest neocon conspiracies.

There is a University of Michigan professor, Juan Cole, who declared during Israel’s war with Hezbollah that the Jewish state was practicing “ethnic cleansing” in southern Lebanon and that Israel tended to start its wars in the summers to avoid censure from American universities who were not in session. There is New York University professor, Tony Judt, who took to the pages of the New York Times to complain that the press was censoring debate on the lobby’s role in pressing for the Iraq war.

President Carter, meanwhile, is flitting around the country saying that Jewish organizations have launched a campaign to discredit his book, “Palestine: Peace Not Apartheid.” Whether they have or not, I have no idea. But if they haven’t, they certainly should, not that it’ll be a difficult task.

There has always been a vocal minority of Americans who side with the Palestinian Arabs. They include academics that have turned the anti-Israel cause into a litmus test for the new left. They have in recent years made common cause with the isolationist right. Every year or so this crowd gins up petitions urging people of conscience to speak out against Israel’s “ethnic cleansing.”

Most political seasons, this combination is about as relevant to mainstream Democratic Party politics as the opinions of, say, the National Organization for the Reform of Marijuana Laws. This year though, it’s a bit trickier.

While no major Democratic candidates call for American direct pressure on Israel to begin dividing Jerusalem or to rail against the occupation of Ramallah, Democrats, today, are careful to walk a fine line on the main threat to the Jewish state, Iran.

On January 23, Senator Edwards told an audience at Herzliya, “To ensure that Iran never gets nuclear weapons, we need to keep all options on the table, Let me reiterate — all options must remain on the table.” He meant the option of a military response to Iran. That earned him contempt from the credulosphere that said he was buying into the Aipac hype about Iran to gin up a new war.

So Mr. Edwards doubled back a month later in an interview with American Prospect online. In response to a question about whether America could live with a nuclear Iran, Mr. Edwards said, “I’m not ready to cross that bridge yet.” He went on to say that he favored direct negotiations with the Iranians and then, amazingly, criticized President Bush for threatening that “all options were on the table.”

General Clark famously told Arianna Huffington that he was sure Mr. Bush would bomb Iran’s nuclear facilities because such speculation was in the Israeli press and he heard it from the “New York money people.”

If there is one issue where the credulosphere is king it is on Iraq. No Democratic presidential aspirant dares cross the netroots on withdrawal from Iraq, and it is such a partisan issue that Aipac has not taken any formal position on the matter. Nor did Aipac lobby for the war resolution in 2002, by the way, or, for that matter, the 1998 Iraq Liberation Act, which made regime change in Iraq an official article of American foreign policy.

Aipac is not pushing the case that staying in Iraq is also important for Israel. It took Vice President Cheney on Monday to make that point. “My friends,” he said. “It is simply not consistent for anyone to demand aggressive action against the menace posed by the Iranian regime while, at the same time acquiescing in a retreat from Iraq that would leave our worst enemies dramatically emboldened and Israel’s best friend, the United States, dangerously weakened.”