The antipathy of African-American members of the United States Congress, known collectively as the Congressional Black Caucus, towards Prime Minister Benjamin Netanyahu could prevent Congress from blocking a nuclear deal with Iran, Newsweek reported on Friday.

The article, by veteran correspondent Jonathan Broder, quoted a congressional aide as saying “the Congressional Black Caucus is gone,” referring to its support for Israel under Netanyahu.

Broder relates how James Clyburn, assistant minority leader and a long-standing member of the caucus, reacted in a meeting with Knesset Speaker Yuli Edelstein shortly before Netanyahu’s address to Congress last month. Edelstein was meeting with members of congress in an effort to reduce the tensions over Netanyahu’s planned speech.

The South Carolina Democrat told Edelstein that he regarded the upcoming speech as an “affront to America’s first black president,” adding an unmistakable racial overtone to a highly divisive political row.

That rancor was heightened on the day of Israel’s Knesset election, when Netanyahu warned that Israel’s Arab citizens were headed to the polls “in droves” to vote him out of office. The premier later apologized for his remark, but his contrition appeared to have no effect on Clyburn and company, Broder wrote.

The immediate consequence of the alienation of the Black caucus could be the inability of congressional Republicans to put together a “veto-proof majority in the House” for a bill that would block a nuclear agreement with Iran.

Ironically, it was precisely to encourage such a bill that Netanyahu undertook his divisive and politically risky congressional address.

Broder explains that President Barak Obama has vowed to veto the two bills currently before the Senate which would essentially prevent the implementation of any agreement with Iran. Overriding a veto requires a two-thirds majority in both chambers – 67 votes in the Senate and 287 votes in the House.

“It’s possible that the Senate’s 54 Republicans could find 13 Democrats and independents willing to cross the aisle,” Broder wrote, but it will be a lot more difficult in the House.

“Assuming all of the House’s 247 Republicans vote to override an Obama veto, they would still need at least 40 Democrats to join them. The Congressional Black Caucus, most of whom don’t rely on pro-Israel campaign donations, has 46 members, the vast majority of whom would fiercely defend Obama’s signature foreign policy effort.” They would be joined by at least two dozen white progressive Democrats who also would rally to prevent a veto override.

Thus, Netanyahu’s speech bring about the opposite result to that intended.