In the Bay Ridge section of Brooklyn, a Muslim woman wearing the traditional hijab head covering is accosted by a man who accuses the woman, an off-duty police officer, of having connections to Islamic terrorists. “Go back to your own country,” the man shouts.

In Nassau County’s Mineola, swastikas and racial slurs are spray painted on a sidewalk, next to the statement, “Make American White Again.”

In Boston, two brothers who beat a homeless Hispanic man tell police that, “Donald Trump was right, all these illegals need to be deported.”

In the month since Donald Trump’s election as president, attacks on many minority religious and ethnic groups have dramatically risen, and the ascendancy of the Republican candidate, who campaigned on a platform of open hostility towards Muslims and Mexicans, is seen in minority communities as fueling this increase in apparent hate crimes. Trump’s appointment of Stephen Bannon, formerly executive chairman of the far-right media outlet Breitbart News, as the president-elect’s senior counselor, has only increased concern in minority communities.

According to statistics compiled by the FBI, the New York City Police Department and the Southern Poverty Law Center, the incidence of bias crimes, against people and property, is up across the country since Trump’s election. Common targets are Hispanics, Arabs, Muslims, African-Americans, members of the LGBT community and Jews.

In Silver Spring, Md., the rector of the Episcopal Church of Our Saviour found a sign advertising Spanish-language services ripped and vandalized with the words, “Trump Nation Whites Only.”

Here, the home of the country’s largest Jewish community, while bias crimes are increasing, Jews have become especially vulnerable. The New York Police Department reported this week a 115 percent increase in hate crimes in the last month, the majority of them, 24 of 43 incidents, against Jews.

“We had a huge spike right after Election Day, it’s somewhat slowed a little bit,” Robert Boyce, NYPD chief of detectives, said. “We’re seeing across the board an increase right now.”

Anti-Semitic public and political discourse is at the highest level in this country since the 1930s, when pro-Nazi sympathy here was acceptable before the U.S.’s entry into World War II, Jonathan Greenblatt, national director of the Anti-Defamation League, said recently. “Jews know what it means to be identified and tagged, to be registered and pulled aside. We must not be silent, we must raise our voices, we must act, and to act we must understand what we are up against.”

While Trump has mildly condemned this post-election outbreak of intolerance, his electoral victory is seen as strengthening prejudice among some of his rabid supporters, particularly members of the self-named “alt-right” movement, right-wing ideologues who traffic in white nationalism, anti-immigration sentiment, nativism, distrust of so-called “Others” and a disdain for “political correctness.”

While no one accuses Trump of harboring anti-Semitic feelings — he has an Orthodox Jewish daughter and son-in-law, and spoken forcefully in favor of Israel’s interests, his supporters point out — his strident tone during the campaign, singling out Mexican immigrants and all Muslims, has created an unhealthy atmosphere.

“Mr. Trump’s rhetoric normalized hate, racism and xenophobia,” Afaf Nasher, executive director of the New York chapter of the Council on American-Islamic Relations, said. “These attacks are the unavoidable byproduct.”

A hopeful byproduct of this current wave of intolerance is an increase of interfaith activities by such organizations as New York’s Jewish Community Relations Council, the Foundation for Ethnic Understanding, the New Jersey-based Sisterhood of Salaam Shalom and the newly formed Muslim-Jewish Advisory Council, founded by the American Jewish Committee and the Islamic Society of North America. These initiatives stress cooperation between Jews and Muslims. (See story on page 14 about a Jewish-Muslim concert in Westchester.)

In a “60 Minutes” interview just after the election, Trump called on people to “stop” hurtful actions committed in his name or in his cause. But he can surely do more to calm people’s fears.

Barack Obama, early in his presidency, faced a similar crisis of conscience. His pastor from Chicago, Jeremiah Wright, drew heavy criticism for a series of intemperate statements about what he called the racist nature of U.S. society.

Obama first tried to dissociate himself from Wright’s incendiary remarks without cutting ties to his old friend, then, in a speech in Philadelphia, finally condemned Wright and resigned from Wright’s Trinity United Church of Christ. Obama said he was “outraged” and “saddened” by Wright’s behavior. “Words that degrade individuals have no place in our public dialogue, whether it’s on the campaign stump or in the pulpit,” he told Charles Gibson of ABC News.

When he met with Obama at the White House after the election, Trump, looking somewhat shaken, said he might seek the president’s counsel. Now would be the time. In the way that Obama full-throatedly rejected Rev. Wright’s words, the president-elect needs an equally full-throated denunciation of the hate being done in his name. A tweet won’t do. And, for the sake of a divided nation increasingly on edge, he should do it sooner rather than later.