By the Jewish Ledger Editorial Advisory Board

The shocking election of Donald J. Trump to be the 45th President of the United States has propelled that American republic into uncharted territory.

The impregnable Rust Belt firewall melted, and the predicted gender solidarity of college-educated white women did not appear. But for one group that was set on edge, the Jews of America, nothing had changed. Four years ago, 69 percent of American Jews voted for President Obama, versus 30 percent for Mitt Romney. That 39-point Obama margin was pretty big, but not as big as the Obama margins for Latino Catholics (54 points), “other faiths” (51 points), and Nones (44 percent).

Last week, 76 percent of American Jews voted against Trump (71% for Clinton; 5% to third-party candidates), versus 24 percent for Trump. That 52-point anti-Trump margin was bigger than the anti-Trump margins for Latino Catholics (48 percent), “other faiths” (42 points), and Nones (48 points).

In other words, among these traditionally Democratic ethno-religious groups, only the Jews shifted away further from the Republican presidential candidate. Why?

Trump attacked Mexicans and Muslims, not Jews. He belittled African-Americans and women and the handicapped, not Jews.

And yes, Trump’s daughter Ivanka converted to Judaism, and her husband, the descendant of Holocaust survivors, is one of his closest advisors.

But Jews know that once it’s open season on minorities, it’s only a matter of time before they’re in the crosshairs.

And indeed, Jewish journalists who wrote critically of Trump have been subjected to vile slurs on social media. We learned of triple parentheses as a secret sign for Jews online, and discovered the encoded anti-Semitic discourse of the alt-right movement. By campaigning against “political correctness,” Trump turned over a rock, and among the things that have crawled out is the xenophobic anti-Semitism of the pusillanimous alt-right.

On Sunday the president-elect announced his first two appointments to the future White House staff. We learned that Steve Bannon will become “chief strategist” in the Trump White House, while Republican National Committee Chairman Reince Priebus will become the new White House Chief of Staff. Bannon, the former head of Breitbart News, specializes in stirring up nativist conspiracy theories concerning invisible international financiers who “suck America dry.” These tropes are rightly regarded as a not-so-faint echo of the notorious Protocols of the Elders of Zion. A white nationalist bigot will be a doorway away from the Oval Office.

America has not seen open and organized anti-Semitism since the 1930s. Could it happen again? Now’s not the time to act as though it can’t.