The dustup over anti-Israel comments made by writers and analysts at the Center for American Progress continued this week, after several pro-Israel organizations criticized the think tank for turning a blind eye to staffers who used terms like “Israel Firster” and accused members of Congress of having an allegiance to the Israel lobby.

The Jerusalem Post’s Benjamin Weinthal spoke to anti-Semitism historian Jeffrey Herf, who saw historical, anti-Jewish connotations in the CAP writers’ comments:

In a telephone conversation with the Jerusalem Post on Tuesday, University of Maryland historian Jeffrey Herf, who has authored books on anti-Semitism, said the phrase “Israel Firsters” is “dangerous.” The notion of “Israel Firsters” “delegitimizes support for Israel” and stokes the “dual-loyalty” charge against American Jews, he said.

The dual-loyalty conspiracy theory existed on “the far Left and far Right of American politics but has not yet seeped into the center of American politics,” Herf said.

CAP blogger Zaid Jilani used the term “Israel Firster” on Twitter several times, but deleted the tweets and apologized after his remarks were publicized. Another CAP blogger, Ali Gharib, was also criticized in the JPost story about his insinuation that Sen. Mark Kirk, an Illinois Republican, was a representative of AIPAC. Gharib made the comment on his private Twitter account:

Gharib wrote that Senator “… Mark Kirk (R-AIPAC) should care about *anyone* other than Israel.”

When asked about Gharib’s statement that the senator from Illinois represents AIPAC, [CAP spokeswoman Andrea] Purse declined to comment. …

[NGO Monitor President Gerald] Steinberg said, “And Gharib’s inference that Senator Kirk is controlled by AIPAC because he supports tough Iran sanctions is equally absurd and sadly reminiscent of campaigns that allege that Jews control American foreign policy. Gharib’s statement also should be publicly condemned by CAP.”

Gharib issued a clarification and apology for his Kirk comment on Twitter yesterday:

One my tweets several months ago, a crude characterization of a senator is being seized upon by critics branding me as an anti-Semite.(1/2)

(2/2) While the accusations are completely false and contemptible, I do apologize for the crudeness of the flippant tweet in question.

Kirk hasn’t weighed in on the controversy yet, but the JPost story has already drawn attention on the Hill. One Republican congressional aide said Gharib’s comment amounted to a charge of “dual loyalty” against a sitting U.S. senator.

“I don’t think you’ll ever see a U.S. senator lower him or herself to respond directly to a relatively unknown fringe blogger but clearly the Jerusalem Post story has forced this issue into the mainstream public debate,” one GOP congressional aide told me. “Gharib’s bosses probably told him he crossed the line and forced him to apologize. In the end, Team Podesta doesn’t want this kind of publicity and they certainly don’t want to be seen accusing U.S. senators who serve in the U.S. military of dual loyalty.”

Questions have also been raised about why stories by CAP bloggers have appeared in the vehemently anti-Israel fringe publication The Electronic Intifada. According to CAP’s spokesperson, EI republished the articles without permission. But critics have pointed out that stories by Gharib and fellow CAP blogger Eli Clifton still remain on EI’s site, despite the alleged lack of authorization.

The CAP saga is a broader reflection of growing internal divisions within the Democratic Party and on the progressive-left. Now that Republicans and the conservative movement have turned support for Israel into a key value issue, anti-Semitic and anti-Zionist segments of the isolationist far-right have found themselves unwelcome in the party. During the past decade and a half they’ve started to swell the ranks of the anti-Zionists in the left-wing pro-Palestinian and anti-war movements. The Democratic Party now has to decide whether it wants to let this strain of anti-Zionism trickle into its mainstream institutions, or whether it will reject these ideas, just like the conservative movement once did.