For American Jews, this fall has become increasingly worrisome. On Thursday alone, the F.B.I. warned of threats to New Jersey synagogues and the Nets suspended Kyrie Irving.Simon Taylor was on his way to an appointment in Flatbush when he pulled into a local filling station one afternoon last week. It was a lovely fall day in Brooklyn, but as he began to fuel up, the climate turned sour: Another customer, spotting the skullcap atop Rabbi Taylor’s head, launched into an expletive-laden rant about how much he hated Jews, and then, when the rabbi photographed his license plate, started chasing him with an upraised fist.Rabbi Taylor, a 58-year-old father of five who oversees social services and disaster relief programs for an umbrella organization of Orthodox Jews, was shaken. A native of England who now lives in Brooklyn, he wondered if the incident was connected to a mainstreaming of antisemitic rhetoric in America.“I’ve never had anything like this in New York, and it definitely felt to me like this whole Kanye West thing had something to do with it,” said Rabbi Taylor, referring to the ugly utterances of the hip-hop legend Kanye West, now known as Ye. “All it takes is a couple influential people to say things, and suddenly it becomes very tense.”For Jews in America, things are tense indeed. Next week’s midterm elections feel to some like a referendum on democracy’s direction. There is a war in Europe. The economy seems to be teetering. It is a perilous time, and perilous times have never been great for Jews.“When systems fail, whether it’s the government or the markets or anything else, leaders often look for someone to blame,” said Jonathan Greenblatt, the chief executive and national director of the Anti-Defamation League, which seeks to monitor and combat antisemitism. “Jews have historically played that role.”Antisemitism is one of the longest-standing forms of prejudice, and those who monitor it say it is now on the rise in America. The number of reported incidents has been increasing. On Thursday, the Federal Bureau of Investigation warned of a “broad threat” to synagogues in New Jersey.Social media has clearly made it easier to circulate hate speech, and that means outbursts like Ye’s, in which he posted on Twitter that he would “go death con 3 On JEWISH PEOPLE,” get more attention. (Many have noted that Ye has about twice as many followers on Twitter as the world’s population of Jews.)Ye’s persistent outbursts have been followed by attention-getting signs of support: In Los Angeles, a group of emboldened antisemites hung a “Kanye is right about the Jews” banner over an interstate on Oct. 22, and then on Saturday similar words were projected at a college football stadium in Jacksonville, Fla.“There’s no doubt that the normalization of antisemitism in the highest echelons of our culture and our political establishment is putting toxins in our eyes and our ears,” said Rabbi Rick Jacobs, president of the Union for Reform Judaism, the largest Jewish denomination in the country. “It’s dangerous, and it’s deadly. It has been unleashed and accelerated in the last few years, and actual attacks have risen.”For many Jewish people across the country, the sense that overtly antisemitic rhetoric is emanating from so many spheres simultaneously is unsettling.The State of the 2022 Midterm ElectionsElection Day is Tuesday, Nov. 8.Biden’s Speech: In a prime-time address, President Biden denounced Republicans who deny the legitimacy of elections, warning that the country’s democratic traditions are on the line.State Supreme Court Races: The traditionally overlooked contests have emerged this year as crucial battlefields in the struggle over the course of American democracy.Democrats’ Mounting Anxiety: Top Democratic officials are openly second-guessing their party’s pitch and tactics, saying Democrats have failed to unite around one central message.Social Security and Medicare: Republicans, eyeing a midterms victory, are floating changes to the safety net programs. Democrats have seized on the proposals to galvanize voters.Steve Rosenberg, a former executive at the Jewish Federation of Greater Philadelphia, said he was put “over the edge” by an incident last weekend in which a prominent basketball player, Nets guard Kyrie Irving, defended his support of an antisemitic documentary (and garnered praise from Ye in the process). On Thursday, the Nets suspended Mr. Irving, citing his “failure to disavow antisemitism.” He posted an apology on Instagram late Thursday night.Mr. Rosenberg said the incident had particular resonance for him because of the current politics of his home state.“In Pennsylvania we are really at a crossroads,” he said, describing himself as a conservative independent who voted for Mr. Trump in 2016 but could not bring himself to vote for either major-party candidate in 2020.Mr. Rosenberg said that this year he is voting for Josh Shapiro, the Democratic candidate for governor, because of his concerns about the Republican Doug Mastriano, who has alarmed many Jewish voters over incidents including criticizing Mr. Shapiro for sending his children to a Jewish day school. (Mr. Mastriano has said his criticism was directed at Mr. Shapiro’s decision to send his children to an “expensive, elite” school, and not based on the school’s religious affiliation.)But his concerns cut both ways. In his state’s race for the Senate, Mr. Rosenberg is voting for the Republican, Mehmet Oz, citing concern that the Democrat, John Fetterman, “will vote with the left-wing woke progressive anti-Israel” faction in the Senate.The years since the election of Mr. Trump — a champion of Israel’s right wing and the father of a convert to Judaism, but also the beneficiary of societal anger that has often had ugly undertones — have seen a rise in attacks against the Jewish community, which some leaders associate with Mr. Trump’s reluctance to distance himself from groups that traffic in antisemitism.At the same time, the left has been rattled by rising divisions within the Democratic Party over Israel’s treatment of Palestinians, pitting those who have traditionally supported Israel against a rising class of progressive activists and lawmakers who ally themselves with the Palestinian cause. It is a fracture that has made the politics of the moment even more complicated for many American Jews.“There’s this constant discussion and debate as to where it is worse — is it worse on the right or the left — when it’s present on both sides, no question,” said Rabbi Moshe Hauer, executive vice president of the Orthodox Union. “There’s been an ascendancy on the right, but there’s also been a very significant uptick on the left, and the evolution of antisemitism on the left is a major development.”A new study by a group of academics including Leonard Saxe, the director of the Cohen Center for Modern Jewish Studies at Brandeis University, found that Jews across the political spectrum are equally concerned about what it calls “traditional anti-Semitism,” but that conservatives are more concerned than liberals about “Israel-related anti-Semitism,” meaning anti-Jewish views that can be conflated with criticism of Israel.There are fissures: In Pittsburgh this week, a group of more than 200 Jews signed a letter criticizing a PAC related to AIPAC, the pro-Israel group, for donating to a Republican congressional candidate, and, in the process, also criticized AIPAC for supporting “lawmakers who have promoted the antisemitic ‘Great Replacement’ conspiracy theory.”A spokesman for AIPAC, Marshall Wittmann, said the organization had opposed the Democratic candidate as a “detractor of America’s alliance with the Jewish state.” Mr. Wittmann said AIPAC had supported 148 “pro-Israel Democrats” this election cycle.Mr. Trump, who remains deeply involved in American politics and has been teasing a possible comeback run in 2024, raised eyebrows when he called on American Jews to “get their act together” by expressing more support for Israel. And recently released documentary footage from last year showed him complaining about his lack of support among American Jews, and asking about the filmmaker, “Is this a good Jewish character right here?”Mr. Mastriano’s wife made a similar point, telling a reporter “we probably love Israel more than a lot of Jews do.” One of Mr. Mastriano’s top advisers recently called Mr. Shapiro “at best a secular Jew.”In a moment in which conspiracy theories about election fraud have established themselves in the mainstream Republican Party, rhetoric about Jewish power takes on an alarming new cast. A poll by the Public Religion Research Institute in 2021 found that almost a quarter of Republicans agreed that “the government, media and financial worlds in the U.S. are controlled by a group of Satan-worshipping pedophiles who run a global child-sex trafficking operation.”“Antisemitism is a conspiracy theory,” said Deborah Lipstadt, the United States special envoy for monitoring and combating antisemitism. “The Jew is seen as more powerful, the Jew is richer, and is smarter but in a malicious way.”Ms. Lipstadt said she sees antisemitism as “the canary in the coal mine” for a broader set of threats to democracy.A thread of antisemitism connects many of the nation’s recent spasms of political violence: the “Jews will not replace us” chants during a white nationalist rally in Charlottesville, Va. in 2017; the “Camp Auschwitz” sweatshirt worn to last year’s attack on the U.S. Capitol; the Holocaust denial in blog posts that appear to have been written by the man accused of breaking into the residence of the House Speaker Nancy Pelosi last week, hoping to break her kneecaps, and, upon not finding her at home, attacking her husband with a hammer.And throughout this year’s election season, troubling rhetoric has surfaced.In Texas, the Republican candidate for railroad commissioner, Wayne Christian, agreed last week to stop using the slogan “vote for the only Christian” after complaints from his Democratic opponent, Luke Warford, who is Jewish.In an email, Mr. Christian said he has been using the slogan since first running for office, has traveled to Israel and has “nothing but love and support for the Jewish community.” But Mr. Warford isn’t buying it. “If you take him at his word that he didn’t know he was running against a Jewish candidate, it’s still an antisemitic thing to say,” he said.Institutional leaders say the anxiety in their communities is palpable. “Many feel we are in a ‘before’ moment,” said Rabbi Noah Farkas, the president and chief executive of the Jewish Federation of Greater Los Angeles.He added: “There’s an old adage that every Jew knows where their passport is.”Last week, the Jewish Democratic Council of America released a digital ad juxtaposing images including rallies in Nazi Germany, the Jan. 6 invasion of the Capitol, antisemitic graffiti and the recent “Kanye is right” banner above the freeway in Los Angeles.On Sunday, Robert Kraft, the owner of the New England Patriots, sponsored a television commercial during the Patriots-Jets game, asking viewers to speak up against antisemitism.Rabbis across the country are grappling with how to address the issue with worshipers. Congregation Beth Elohim in Brooklyn this week sent an email to its members announcing a sermon this weekend on antisemitism, noting the upcoming election as well as news coverage of rising antisemitism, and saying, “It is difficult not to feel anxious about the future.”Younger Jews sense a shift in society. “For people of my parents’ generation, there was a certain sense of safety with regard to antisemitism in America,” said Meshulam Ungar, a 21-year old junior at Brandeis and a vice president of the Brandeis Orthodox Organization. “Things have gotten more dangerous for us.”The consequences of antisemitism are on vivid display in the culture right now. A new Ken Burns documentary, “The U.S. and the Holocaust,” was released in September by PBS and details how American antisemitism affected the nation’s willingness to take in refugees fleeing Nazi persecution. On Broadway, the best-selling new play of the fall season is Tom Stoppard’s “Leopoldstadt,” about three generations of a Jewish family in Austria largely destroyed by World War II.Brandon Uranowitz, one of the play’s leading actors, said performing a story about the deadly effects of antisemitism in this climate has become both more painful and more important. “All of a sudden, objects in the mirror are closer than they appear,” he said.Off Broadway, a group of artists is staging an unexpectedly timely revival of “Parade,” a musical about the antisemitism-fueled 1915 lynching of a Jewish man in Georgia. Ben Platt, that production’s star, made a similar observation, saying, “It’s felt urgent in a way that is shocking to all of us.”Meanwhile, tragedies of terror loom in recent memory for many — including the 2019 killing of a woman at a California synagogue by a gunman shouting about how Jews were ruining the world, and this year’s hostage-taking at a Texas synagogue by a man complaining about Jewish power.Rabbi Jeffrey Myers has watched the steady stream of headlines about antisemitic rhetoric — and the sometimes muted responses to it — with sadness and horror. “When people don’t speak up, their silence is deafening,” he said.Rabbi Myers was speaking the day after the fourth anniversary of the killing of 11 people at Tree of Life, his synagogue in Pittsburgh. The gunman later told police he “wanted all Jews to die.” Rabbi Myers survived the shooting, which remains the deadliest attack on Jews in American history.“Speech is just the beginning,” Rabbi Myers said. “It moves from speech to action.” More