Today, April 24, is Yom HaShoah, or Holocaust Memorial Day — and never in my lifetime has it seemed more necessary or more relevant.

As the child of a Holocaust survivor, who himself is no longer here to testify, I have always felt a great personal responsibility to bear witness. I spent years collecting, writing and publishing my family’s tragic story.

I promoted the construction of memorials, both here in the United States and in Europe. Naively, I thought the battle over the memory of the six million Jews murdered by the Nazis during World War II had been won. After all, we succeeded in erecting Holocaust museums and memorials in every major US city — even in places like El Paso, Texas and Terre Haute, Indiana.

I watched with satisfaction as the Shoah was deeply ingrained and widely explored in US popular culture with movies like Schindler’s List, The Pianist and Life is Beautiful, as well as many others. Several states — including New York, California, Illinois, Florida, New Jersey and Michigan — passed laws mandating that all children learn about the Holocaust in school.

The events of the past year have shattered my complacency.

First, as a presidential candidate, Donald Trump allowed his campaign to exploit images and memes clearly drawn from the history of anti-Semitism. Then, in February, his White House issued a statement on International Holocaust Memorial Day excluding mention of the Jews as primary target and victims of the historic crime against humanity.

Nearly two weeks ago, White House spokesman Sean Spicer outrageously claimed that Syrian President Assad’s use of poison gas against his own people exceeded in horror the Nazis’ industrial-scale use of poison gas to murder millions of people, primarily Jews. Spicer showed his insensitivity and ignorance by coining the cleansing term “Holocaust centers” to describe the Nazi extermination camps.

As if this was not enough, we also have the specter of a leading French presidential candidate, Marine Le Pen, denying French culpability for the round-up and deportation of thousands of Jews to German camps, where most died during World War II.

In our own country and around the world, there seems to be a rising tide of discriminatory and exclusionist nationalism, exploiting fears and demonizing “the other” for political gain. Time and again, leaders of this trend have demonstrated a shocking disregard for the facts, details and lessons of the Holocaust.

Apparently, in an age of “fake news,” “alternative facts” and rising xenophobia, we can no longer assume that the facts of the Shoah are widely accepted, or even known. Spicer’s comments are instructive. Given the endless list of movies, books, plays, works of art and even graphic novels with Holocaust themes that have saturated the culture, it must have taken extraordinary efforts for someone like Spicer — an educated and well-informed individual in the thick of US politics — to close his eyes and ears to them.

Presumably, the message of the Holocaust is not one that they are much interested in hearing — or understanding.

What about the message might they find objectionable? Perhaps the fact that vilifying, demonizing and targeting an entire ethnic or religious group can lead to catastrophe? That refusing aid and refuge to refugees fleeing conflict can doom them to a horrific fate? That such acts of cruelty may begin small but have a terrifying way of expanding?

For those of us concerned with preserving Holocaust memory, there are lessons too. We must consider whether we have focused too much on the chronology and mechanics of the Shoah and too little on the universality of its message, on its urgency and continued relevance in our times.

I do believe that the Holocaust is a birthright we must handle with care. We cannot allow its lessons to be cheapened by misuse or diluted by overuse.

But neither is the Shoah an historical artifact to be guarded and preserved in museums and archives. It is a living legacy that summons and challenges us in all of our political work here, in Israel and around the world.

It is a touchstone for all we do and all we are. And this year of all years, the challenge is stark and the task is clear.