The politics of anti-Semitism intensified this week, with Jews blaming one another for not properly dealing with the spike in anti-Jewish incidents in the U.S. last year — and for even failing to recognize anti-Semitism when they see it.

A case in point is Cynthia Nixon, the former “Sex and the City” star who announced Monday that she will seek to wrest the Democratic nomination for New York governor from incumbent Andrew Cuomo. In 2010 she signed a letter in support of a boycott by Israeli artists, who were refusing to perform in the West Bank settlement of Ariel. Now, law professor Alan Dershowitz is saying that action has disqualified her as a candidate.

“She has collaborated with Israel haters Jewish Voice for Peace and Vanessa Redgrave in boycotting Israel,” he tweeted last Friday. “Do not support her bigotry.”

On the other hand, just a year after signing the letter, Rabbi Sharon Kleinbaum, spiritual leader of Congregation Beit Simchat Torah, told Nixon: “We’re proud of you as an artist, we’re proud of you as an activist, we’re proud of you as a partner and as a parent.”

This partisan divide was visible again earlier this month when Nation of Islam leader Louis Farrakhan delivered a sermon in which he called Jews “satanic” and said they are “the mother and father of apartheid” and responsible for “degenerate behavior in Hollywood.” Sitting in the audience was Tamika Mallory, a co-president of the Women’s March organization that led the anti-Trump protests after his election. Farrakhan praised her and the group, and she later posted a picture of herself and Farrakhan on Instagram.

Two other leaders of the Women’s March, Carmen Perez and Linda Sarsour, have also praised Farrakhan. In fact, Sarsour spoke at a Nation of Islam event in 2015. And Perez, when asked about Farrakhan, reportedly refused to repudiate his anti-Semitism, saying simply: “There are no perfect leaders.”

Several days later, the Women’s March issued a statement denouncing Farrakhan’s “anti-Semitism, misogyny, homophobia, transphobia and racism.”

These are just the latest examples of how fighting anti-Semitism is complicated by the political divide in America. Those on the political left point to the growth of the alt-right movement along with the presidential campaign and election of Donald Trump. They cite last August’s white nationalist torchlight march in Charlottesville, Va., that was punctuated with anti-Semitic chants, and attended by members of the Ku Klux Klan, neo-Nazis and other extremists, one of whom killed a woman by driving into a crowd of counterprotesters.

But they are also painfully aware of the damage the Women’s March organizers have caused. As Audrey Sasson, executive director of Jews for Racial and Economic Justice, wrote, “A painful truth about working to build powerful movements for justice across many communities is that sometimes we disappoint and hurt one another, especially in times of great stress. … Since the incident became public in a flurry of media coverage, JFREJ has worked — often behind the scenes — to engage with the Women’s March and other stakeholders. …. While we may have very real reasons to feel hurt, we also know that there are people all too eager to cynically capitalize on this moment to destroy one of the most powerful groups to rise up in resistance following the 2016 election.”

Sasson added that her group still believes the Women’s March is a “powerful force and a valued partner” in the broader movement against the rise of the far-right.”

The group’s website also spells out the different ways the political left and the political right work to fight anti-Semitism. The political right, it said, tends to restrict itself to a defense of Israel and of Palestinian oppression. Those on the political left work with others in an effort to defeat anti-Semitism — and that “necessarily includes Palestinians.”

“Therefore, the left must commit to a strategy for fighting anti-Semitism that also entails Palestinian liberation,” it said.

All of this, suggested Haaretz correspondent Allison Kaplan Sommer, illustrates that in “today’s charged environment, the American-Jewish community is often simply too divided to define what anti-Semitism is — making it impossible to combat it in a unified fashion. Nearly all Jews can call out an anti-Semite sporting a Nazi uniform or a Klan robe. But without such clear visual cues, anti-Semitism is too often in the eye of the beholder.”

Natan Sharansky, chairman of the Jewish Agency, offered this week his own definition of anti-Semitism: Jews who profess to love fellow Jews cannot also say they hate Israel, and Jews who hate Israel cannot be considered friends of the Jewish people. You can’t have it both ways, he insisted during a panel discussion at the sixth Global Forum for Combating Antisemitism in Jerusalem.

Sharansky was quoted by the Jerusalem Post as saying Jews should not work with those on the left who are tainted by anti-Semitism — such as Sarsour and Black Lives Matter — as well as the far-right, racist parties in Europe just because they claim to support Israel.

“There are forces that at the moment look very important to us, but they are hostile to the [local] Jewish communities and cannot be our friends,” Sharansky was quoted as saying.

His comments came as an essay last Sunday by New York Times editor, Jonathan Weisman, accused American Jewish leaders of being “remarkably quiet” about the surge in anti-Semitic incidents in the U.S. They are more concerned, he argued, with Israel. The one Jewish group that focused on the increase in anti-Semitic incidents is the Anti-Defamation League, he wrote, noting that it recently released figures showing a 57 percent increase in such incidents last year — the largest one-year jump on record. And in return, he said, the ADL “was tarred as a partisan organization by an elected Jewish Republican,” Ohio state treasurer, Josh Mandel.

“The Jewish community has been extremely vocal about anti-Semitism in the last year-and-a-half and beyond that,” said Rabbi Jill Jacobs, executive director of T’ruah: The Rabbinic Call for Human Rights. “We have been speaking out about white supremacy, the dog whistling of Trump, Steve Bannon [Trump’s former chief strategist], and anti-Semitism when it shows up on the left,” she insisted.

Mandel did not respond to two phone messages requesting comment. But leaders of other Jewish organizations vehemently pushed back against Weisman’s claims that they have been silent.

“The Jewish community has been extremely vocal about anti-Semitism in the last year-and-a-half and beyond that,” said Rabbi Jill Jacobs, executive director of T’ruah: The Rabbinic Call for Human Rights.

“We have been speaking out about white supremacy, the dog whistling of Trump, Steve Bannon [Trump’s former chief strategist], and anti-Semitism when it shows up on the left,” she insisted. “Close to 2,000 rabbis of all denominations have been on the streets with their community members protesting anti-Semitism, xenophobia, racism and Islamophobia.”

Daniel Elbaum, senior associate executive director of the American Jewish Committee, maintained that the AJC has spoken out against anti-Semitism, whether it comes from the right or the left. He was also critical of Weisman for not mentioning the “horrifically anti-Semitic speech” of Farrakhan.

Weisman told The Jewish Week that he anticipated such responses but he said that groups such as the AJC “do not want to offend their conservative donors who turn a blind eye to the white nationalist support Trump received because they are afraid their donors will dry up. … How strongly Jewish groups are speaking out is a matter of opinion.”

He said a check online of AJC statements decrying anti-Semitic incidents revealed that all but a handful concern incidents overseas.

Reached by phone from Jerusalem where he is attending the Global Forum for Combating Anti-Semitism, Daniel Mariaschin, B’nai B’rith International CEO, criticized Weisman for “not looking deeply into what is being done to fight anti-Semitism.”

He insisted that much of the anti-Semitism today is sparked by “those who call themselves anti-Zionists and who engage in demonizing Israel.”

“We are always looking for friends and allies, and the assumption that we are not fighting anti-Semitism on all fronts is a mistaken one,” Mariaschin said.

Asked about this week’s Global Forum in Jerusalem, Weisman said: “I would like to see that conference in Washington.”

Among the other Jewish leaders who took issue with Weisman’s article were:* Rabbi Marvin Hier, dean of the Simon Wiesenthal Center, who pointed out that much of the anti-Semitism in America and Europe today “is directly and indirectly related to Israel.” He said his organization is not silent when it comes to speaking out about anti-Semitism but that the media – he singled out the New York Times — does not cover it.

“Why is an Israeli settlement issue front page coverage?” he asked. “If it has to do with the United Nations bashing Israel, that is top coverage.”

* Daniel Mariaschin, B’nai B’rith International CEO, criticized Weisman for “not looking deeply into what is being done to fight anti-Semitism.”

In a phone call from Jerusalem where he is participating in the Global Forum for Combating Anti-Semitism, he too insisted that much of the anti-Semitism today is sparked by “those who call themselves anti-Zionists and who engage in demonizing Israel.”

“We are always looking for friends and allies, and the assumption that we are not fighting anti-Semitism on all fronts is a mistaken one,” Mariaschin insisted, adding that it is very important that the Trump administration appoint a new special envoy to deal with anti-Semitism worldwide.

“I have seen how that position can really help us in this fight because the envoys have traveled the length and breadth of the world to bring the concern of the U.S. administration, members of Congress and their constituents to areas where anti-Semitism raises its head.”

* Rabbi Steven Wernick, chief executive officer of the United Synagogue of Conservative Judaism, said the increase in anti-Semitic incidents and the “normalization of anti-Semitic acts” has heightened the “feeling of greater vulnerability, but we have the SCN [the Jewish community’s Secure Community Network] and the cooperation of Homeland Security, the FBI and local law enforcement. … We support the ADL and sign onto their statements.”

* Rabbi Rick Jacobs, president of the Union for Reform Judaism, said “American Jewry can, must, and is, fighting back against anti-Semitism on the left and the right and all hate crimes, even as we also concern ourselves with Israel. Thousands of lawn signs are in front of homes and synagogues reading: `No Place for Hate.’”

* William Daroff, senior vice president for Public Policy at the Jewish Federations of North America, pointed out that after Charlottesville federations nationwide worked with law enforcement and local government leaders “to prevent similar incidents from happening in their communities. …Anti-Semitism takes many forms today, and we continue to speak up loudly against them and to adapt to fight these challenges by building strong and resilient Jewish communities.”