For decades, black civil rights leaders have worried that black Americans’ largely automatic support for Democrats has led the Democratic Party to take their votes for granted. Against a backdrop of frightening anti-Semitism in Europe, the increasingly aggressive use of anti-Jewish tropes by the President of the United States to attack critics of his nuclear deal with Iran has begun to raise similar concerns among American Jews, the Democratic Party’s second-most reliable constituency.

It was Republican Secretary of State James Baker during the George H.W. Bush administration who famously derided Jews thusly: “(Blank) ’em. They don’t vote for us anyway.” Baker was not wrong. Democratic candidates have won 60 percent or more of the Jewish vote in 21 out of 22 presidential elections since 1928.

But having failed in his effort to block the American peoples’ representatives in Congress from reviewing his nuclear agreement with Iran, President Obama will likely find himself required to use his veto to override both American public opinion and Congress. A recent Quinnipiac poll found that Americans oppose the deal by a 2-1 margin, and Congress will vote to disapprove it. It is not difficult to see why. The arrangement will surrender all diplomatic and economic leverage over Iran, provide the world’s foremost state sponsor of terror with some $150 billion to acquire conventional and ballistic weapons, remove international restrictions on such acquisitions and virtually guarantee that Iran will obtain nuclear weapons some 10 to 15 years from now.

Even though all he needs in order to sustain his veto is to persuade most fellow Democrats to stick with him out of party loyalty, the President has doubled-down on his strategy of blaming the widespread opposition to his deal on Jews, using malodorous rhetoric suffused with coded bigotry.

Criticism of his deal, our President says, is the work of “money,” “donors” and “lobbyists” who “demand” war, and whose “drumbeat for war” is motivated by their “affinity for … Israel.” The specter of an American president using the time-honored rhetorical weapons of anti-Semites to improve poll numbers has been sickening to many, but perhaps most of all to American Jews who voted to elect and then re-elect him.

Indeed, the Anti-Defamation League, the venerable civil rights organization, has condemned the Obama White House in unusually strong terms. “[T]he Administration,” it said on July 20, “should desist from the kinds of demagogic accusations and insinuations claiming that opponents of the deal are warmongers.”

That the White House veto of Congress’ resolution of disapproval of the Iran deal seems likely to prevail has not softened its furious attacks on skeptics, or diluted its efforts to generate support by turning Americans against Israel and American Jewry. It has embraced the obverse of Baker’s formulation. “Blank ’em,” is the Democratic administration’s apparent attitude toward the Jewish community. “They’ll vote for us regardless.”

It may be right. Jews have little sympathy for Republican positions on civil rights, marriage equality and reproductive freedom, among others. Still, while they have been staunch supporters of Democratic Party and Obama, there was some evidence that the latter’s conduct and the former’s tacit support for it had taken its toll even before the administration turned truly poisonous.

According to Gallup, in 2008, 71 percent of Jews identified as Democrats; by 2014, it was down to 61 percent. Obama’s approval rating among Jews was 77 percent in 2009; by March 2015, it was 54 percent.

The President’s purposeful use of language fraught with bigotry would be a stain on his presidency under any circumstances. That he has employed the very divisive rhetoric he professes to abhor in order to bypass the American people on a matter fundamental to their national security, and to intimidate those who sincerely believe his course on Iran is dangerous, only deepens that stain. It is a stain painful for all Americans, and not only Jewish-Americans, to contemplate.

This op-ed originally appeared in the Boston Herald.