Back in August, though, when asked for her stand on the movement, she said only that BDS is “not helpful in getting [a] two-state solution.” Her listeners reasonably assumed that her words constituted a rejection of BDS. Now they know better.

Such attitudes (not to mention such dissembling) on the part of political “progressives” are no surprise, of course, although, as I argued last week, the Democratic Party, at least for the foreseeable future, is still firmly under the control of cogent and rational people.

Still and all, it’s sensible that many of us are concerned with disreputable forces on the edges of the political left.

What should concern us, though, no less, in fact, I think, more, are violent ones on the other end of the political spectrum.

Pittsburgh, although its death toll was unprecedented for an attack on Jews in the U.S., wasn’t an outlier.

Right wing anti-Semitism was likewise behind the attacks in 2014 just before Pesach at the Kansas City Jewish Community Center. And, before it, the 2009 Holocaust museum shooting in Washington, D.C. And before it, the 1999 Jewish Community Center shooting in Los Angeles.

Reactionary sentiment, of course, was also behind the 2015 murder of nine people at a church in Charleston, South Carolina. And behind the killing of two elderly African-Americans at a supermarket near Louisville, Kentucky last month. As it was behind the letter bombs mailed to prominent Democrats and liberals mere weeks ago.

And last week, an acquaintance of Robert Bowers, the murderer of the 11 Jews in Pittsburgh, was arrested near Washington, D.C. on gun charges, after the FBI said he posted on a social media site that the massacre “was a dry run” and that “there was more to come.”

The 30-year-old man, Jeffrey R. Clark Jr., was charged with transporting firearms across state lines and possession of four illegal high-capacity magazines intended for use with AR-15 weapons, a favorite of American mass shooters (and used by Bowers), as well as two kits for converting those semiautomatic weapons into fully automatic rifles. A search of the suspect’s home also yielded a shotgun, a rifle and two handguns. And two ballistic vests, two ballistic helmets and two gas masks.

Family members, who notified authorities, said that Mr. Clark had been “heavily involved” in the alt-right movement.

The FBI said that the arrestee and his younger brother, who, as it happened, committed suicide shortly after the Pittsburgh massacre, had attended last year’s “Unite the Right” rally in Charlottesville, Virginia, and family members told agents that the brothers had photos of themselves from the event standing with James Alex Fields, the man charged with murder for driving a car into a crowd of protesters in Charlottesville, killing a 32-year-old woman and injuring 19 other protesters.

The agents were also told that the Clark brothers admired Oklahoma City bomber Timothy McVeigh, “Unabomber” Ted Kaczynski, and the late murderous cult leader Charles Manson (who famously carved a swastika on his forehead).

Clark posted his feeling that “every last one” of the Jews killed in Pittsburgh “deserved exactly what happened to them and so much worse,” and he considered Bowers a “hero.”

In fact, according to the Anti-Defamation League, a majority of the hatred-fueled murders in the U.S. last year were perpetrated by right-wing extremists.

And an ABC News/Washington Post poll taken last year showed that more than 20 million Americans called it “acceptable” to hold neo-Nazi or white supremacist views.

20 million.

The Amora Abba Binyamin (Brachos 6a) teaches us that, were the myriad mazikin (dangerous entities)that constantly surround us actually visible, we would be frozen in terror. Whether he had in mind ethereal entities, or, perhaps, the fungi, protozoa, bacteria and viruses that regularly seek to invade our bodies but are thwarted by the brachah of our immune systems, must remain in the realm of speculation.

But there are also countless entirely human mazikin out there, unseen people whose consciences, if one can characterize their fundamental mentalities that way, not only don’t prevent them from inflicting harm on others but impel them, when encouraged, to actively do so. And those others will always include, prominently, Jews.

So, while our alacrity regarding political developments on the left with potential to harm Israel shouldn’t wane, in the backs of our minds — actually, in their forefronts — should be an awareness of the all too clear and present danger of murderous violence in the anti-liberal universe.