"I sort of expect [criticism] from a long involvement in activist politics," Bender said.
But this backlash was especially intense: Some who claim CAIR is a terrorist-friendly group see Bender's employment there as a treasonous public-relations ploy.
"It is obligatory to out the traitors in our midst," conservative Zionist blogger Adina Kutnicki wrote of Bender. "This . . . is a matter of Jews aiding and abetting those who seek nothing less than Israel's destruction, and by definition, the murder of half of world Jewry."
Even the more mainstream Anti-Defamation League expressed milder concerns about Bender, while condemning the name-calling as hate speech.
"Time will tell," said Nancy K. Baron-Baer, the league's associate regional director in Philly. "The fact that Jacob Bender is Jewish does not necessarily indicate a change of attitude and activity at CAIR. Unfortunately, there are Jews who can be anti-Jewish and anti-Israel. Bender's views already on the record are not encouraging. But, we will wait and see."
With his Santa Claus hair and soft-spoken demeanor, Bender doesn't seem intent on destroying Israel and murdering half of world Jewry.
In fact, he's surprisingly understanding of his haters.
"No one can predict how people react to suffering or the knowledge of suffering," he said. "So some Jews who came out of World War II and their children understand the Holocaust as meaning that everyone in the world was and will continue to hate the Jews."
He added: "Being called a Jewish Nazi-lover is not the nicest thing. But it speaks more about the intolerance of those making the charges than it does about CAIR."
But Bender has been sharply critical of Israel's occupation of Arab territory captured in the 1967 war and its settlements in those territories.
He doesn't help himself, either, with his critics by refusing to say whether he supports Israel's right to exist or believes a two-state solution is the path to peace. Such questions are "complicated" and not worthy of "superficial answers," he said.
Inspired by MLK
Bender's passion for peace stretches back to his childhood.
At 12, he heard Martin Luther King Jr. speak in Los Angeles, where he grew up. He remembers marching for civil rights and against the Vietnam War and nuclear testing.
He fervently believes in tikkun ha-olam, a Hebrew phrase that means "repairing the world."
"There's a long Jewish tradition of social activism based upon that religious mandate," he said.
After studying filmmaking and religion in college, Bender created a career that often melded those two passions.
He lived in Israel for five years in the 1970s, working as an audiovisual producer at the Yad Vashem Holocaust Museum in Jerusalem, as well as for the Israel Ministry of Education.
More recently, he completed "Out of Cordoba," a 2010 documentary examining the relationships among Muslims, Christians and Jews that has had about 130 public screenings.
He wrote speeches on interfaith affairs for Jesse Jackson during the civil-rights leader's 1984 presidential campaign. He has pleaded for peace before everyone from Palestinian leader Yasser Arafat to Saudi Arabia's King Abdullah and Jordan's King Hussein.
After the Sept. 11, 2001, attacks, he helped facilitate interfaith talks with American Muslims, speaking at mosques and Islamic conventions. And peace is a family affair: His wife works for September 11th Families for Peaceful Tomorrows, relatives of 9/11 terror attack victims who now advocate for peace.
At CAIR, he will champion the rights of the region's 200,000 Muslims.
Most problems reported to CAIR-Philadelphia involve workplace discrimination or profiling by law enforcement, said Amara Chaudhry-Kravitz, the chapter's legal director.
Since 2010, pleas for legal help from those alleging anti-Muslim profiling or bias by law enforcement or the court system have risen 300 percent, she said.
Reported hate crimes against Muslims are rare. Still, just a few weeks into the job, Bender found himself hosting a news conference and demanding a state and federal investigation into vandalism at a Newark, Del., mosque, where thugs defaced signs, tore down fences and posted a cross. Three juveniles were later arrested.
Bender's Jewish roots initially sparked some hesitation when CAIR's local leaders began mulling a new director for Philadelphia, said Iftekhar Hussain, who chairs CAIR's Pennsylvania board of directors.
"We thought: 'Well, he's Jewish, and oh my God, what will people say?' But Muslims haven't come up to me and said: 'My God, why did you hire a Jew?' " Hussain said. "His work shows a lot of effort - and achievement - to build relationships between Muslims and Christians and Jews."
Chaudhry-Kravitz, a Muslim who is married to a Jewish man, said the criticism of Bender's background "surprises and disappoints me, because CAIR has quite a few non-Muslim employees, as well as other Jewish employees."
"We're being portrayed as so bigoted and narrow-minded that we limit our employment decisions to our own communities. We're a much more diverse community than that," she said.
Chaudhry-Kravitz says she's well used to the suspicion. "The assumption is if you work for a Muslim organization, you are sympathetic to radical Islam and jihadist sensibilities," she said.
Other peace activists applauded Bender's appointment.
"This was a daring thing for CAIR to do," said Rebecca T. Alpert, a Temple University religion professor and rabbi who also was named to the "Jewish S.*.*.T. List" for her interfaith advocacy. "Prejudice is an evil. Sometimes it lights on the Jews; sometimes it lights on the Muslims; sometimes, African-Americans, women or gay people. We have to take care of each other, recognize prejudices when we find them and try to root them out."
On Twitter: @DanaDiFilippo