From the left: Joe Biden’s Fall to Earth

For months, Joe Biden assumed he could “project confidence and calm, and the delegates would fall into his lap,” observes The New Republic’s Alex Shephard. But after he “responded like a deer in headlights” to Sen. Kamala Harris’ attacks in the first debate, Biden has had to shift gears. Unable to “coast to victory on a bleached white smile, several hundred million dollars in corporate money and endless references to his former boss,” he is doing more events and interviews and talking policy. But he clearly isn’t prepared “to act like a normal candidate”: “He tends to stumble” when defending his ideas and his record. Bottom line: “Now Biden must actually try to win over voters” but “appears to be struggling with the concept.”

Hate watch: ‘Invisible’ Anti-Semitic Attacks in Brooklyn

At Tablet, Armin Rosen sounds an alarm: “The increase in the number of physical assaults against Orthodox Jews in New York City is a matter of empirical fact.” Such attacks spiked from “17 in 2017 to 33 in 2018, with the number for the first half of 2019 standing at 19,” according to the latest NYPD data. And the statistics likely miss the full scale of the crisis, “since reporting is often time-consuming or interferes with religious observance.” So why haven’t city authorities responded more vigorously? Maybe it’s because “the victims are most often outwardly identifiable, i.e., religious rather than secularized Jews, and the perpetrators who have been recorded on CCTV cameras are overwhelmingly black and Hispanic” — which inverts the liberal identity-politics narrative and leaves even Jewish groups feeling ­uncomfortable. Or perhaps it’s because “like the collapse of the transit system . . . anti-Semitism is a challenge that feels too large for the city to meet.”

From the right: Living in an Age of Amnesia

At Quillette, Joel Kotkin reviews the perils of what Saeed Akhter Mirza has called this “Age of Amnesia.” Especially in the West, “We are discarding the knowledge and insights passed down over millennia and replacing it with politically correct bromides cooked up in the media and the academy.” With dogma privileged over open inquiry, “a worrying number of students possess remarkably little knowledge of history or of how civilization developed.” Now, “40 percent of American Millennials favor limiting speech deemed offensive to minorities.” And Millennials are also far more likely to be dismissive of basic constitutional civil rights.” The peril: “If one does not even know about the legacies underpinning democracy, individual freedom, and open discussion, one is not likely to miss them when they are eroded.”

Conservative: A New Vision for Space

In the 50 years since America landed a man on the moon, “we have made our economy and our national security utterly dependent on space,” points out ex-Rep. Bob Walker at The Ripon Society. But now “space has become a place of confrontation and potential conflict,” with the threat from other countries “so critical that a [military] branch with space as its total focus is necessary.” President Trump’s Space Force would “organize, train and equip military personnel to respond to threats we face in and from space.” To drive “technology development,” Trump is also pushing NASA to work “in conjunction with the entrepreneurial space businesses.” Team Trump’s emphasis is vital, because “the past ­record shows us when we lead in space, we lead on earth.”

Education beat: More Recess for Better Test Scores

More recess could be key to boosting student test scores, Jack Whitney reports for Dallas’ D magazine. The program LiiNK (Let’s Inspire Innovation n’ Kids), created by Debbie Rhea of Texas Christian University, involves four 15-minute unstructured recess breaks a day, plus “a character-development component in the curriculum.” In the eight districts using ­LiiNK, he finds, “teachers, administrators and parents raved about its effects on students. The additional recess, they said, helped their kids focus better, misbehave less and even lose weight.” A veteran third-grade teacher told him, “This year was hands down, the easiest year I’ve had with [student] behavior.” Some data and other studies suggest LiiNK is the way to go, even though in most US schools “the focus on testing has led to wide cuts in recess” in recent years.

— Compiled by The Post Editorial Board