At his press conference last week, President Trump tongue-lashed a Jewish reporter who innocently asked about “an uptick in anti-Semitism.” The president instructed him to be “quiet,” denouncing the question as “repulsive.”

It wasn’t until yesterday that Trump denounced an outbreak of threats against Jewish community centers as “horrible” and “painful.” In remarks made following a tour of the National Museum of African American History and Culture he said such threats are a “very sad reminder of the work that still must be done to root out hate and prejudice and evil.”

That response came a month into his administration, which had until then been rather clueless about what is not just an “uptick” in anti-Semitism but a surge, not only abroad but throughout America.

Here in Massachusetts, the Anti-Defamation League reports that the number of anti-Semitic incidents — from vandalism to online cyber hate — was greater in 2016 than in 2014 and 2015 combined.

For several decades after World War II, American anti-­Semitism was largely the domain of those who lived under rocks. It then leeched into the comment sections of websites. It has now emerged into the daylight, generally advanced by individuals who claim stoutly that the last thing they are is anti-Semitic. There is extant a kind of anti-Semitic pincer movement.

From one flank there is a witches brew of the alt-right — from the barely to totally unhinged neo-nationalists and de facto white supremacists — enabled by millions more who stand behind them.

The other flank is a noxious stew of Islamic extremists and those who indulge them and the Boycott, Divestment and Sanctions, or BDS, crowd, a Palestinian-based umbrella group devoted to the elimination of Israel but clever about the way they package their efforts for public consumption. Indeed, when it comes to the targeting of Israel, both flanks often find themselves working in concert, a marriage not only of strange bedfellows but of the vile and the misguided.

One prominent Democrat who has given the BDSers the back of this hand is New York Mayor Bill DeBlasio. “There are plenty of people who support BDS who … call themselves progressives,” DeBlasio said last summer. “Defending Israel is a matter — from my point of view as a progressive — consistent with progressive values.”

In Massachusetts, dozens­ of state legislators have signed onto a bill introduced by state Sen. Cynthia Creem (D-Newton) that would place Massachusetts taxpayers on record as standing up to the effort to strangle the Jewish state. The legislation would require those seeking to be subsidized with state contracts to certify that they will not refuse to do business with someone based upon their “race, color, creed, religion, sex, national origin, gender identity or sexual orientation.”

Some on the left, who are fine with every other aspect of the bill, object to it because it would also require those seeking state money to agree not to discriminate against Israelis. They argue that the bill violates the First Amendment because it would “chill” the rights of those who want to boycott Israel.

Of course, it does no such thing. Those who wish to boycott Israel, like those who wish to make racist comments or discriminate in their private lives, may still do so. But that doesn’t translate into a right to demand that the commonwealth of Massachusetts subsidize their discrimination with taxpayer dollars. In effect, the opponents of the bill find themselves in what should be the embarrassing position of seeking to create a “safe space” for discrimination against the Jewish state, and to make Massachusetts taxpayers their accomplices.

Of course, the bill’s opponents would also make Massachusetts workers their victims. A study by Stax, Inc., a research firm, found that Israeli-founded businesses generate significant revenue and jobs in Massachusetts. According to Stax, Israeli-founded companies provided over $18 billion in economic benefit to the commonwealth in 2015, employed 9,000 people here and supported an additional 27,000 jobs.

The BDS crowd, of course, could not care less. Their mission is to pull wool over eyes. With any luck, and a bit of homework on their part, Massachusetts legislators will not be snookered. The Creem bill is one which deserves support — and particularly the support of those who take their progressivism seriously.

Jeff Robbins, an attorney in Boston, is former chief counsel to the minority of the U.S. Senate Permanent Subcommittee on Investigations.