On such a Thanksgiving week as this, when Donald Trump sends soldiers to turn away desperate immigrants seeking asylum; when he sells a piece of America’s soul to salvage an arms deal with a murderous Saudi Arabian prince; when he foists upon us a flim-flam businessman as acting attorney general; when he boasts about U.S. military might but can’t bring himself to visit a cemetery at a world war centennial commemoration – at such a time as this, we recall the events of precisely 55 years ago, in the hour we lost John F. Kennedy.

To those of us who were alive back then, Nov. 22, 1963, is still the most shocking day of our lives, even more than Sept. 11, 2001. We were a more innocent nation back then. And Kennedy had us still believing in the special character of those who occupy the White House.

Some of it was myth, but a lot of it was not. He appealed to the best of our nature, not the basest. When he urged us to “ask what you can do for your country,” it was a summon to arms, to selflessly do for others what only idealistic Americans can do.

When we see Donald Trump change Adam Schiff’s last name with two t’s replacing the final f’s, we’re reminded how vulgar our discourse has fallen since Kennedy turned political rhetoric into poetry.

We’ve come from Kennedy, who showed his heroism in World War II, to Donald Trump who unconscionably sneers at the prisoner of war John McCain, who diminishes those warriors who finally got Osama bin Laden, who walks away from all those lying in soldiers’ graves.

Kennedy made us want to be better than we were. He inspired us to rescue distant primitive people, one Peace Corps mission at a time. He championed racial fairness. He understood we are a nation of immigrants, which is our great strength. Trump wants to put up walls to keep out all dark-skinned people, no matter their desperation.

Kennedy got us through the Cuban missile crisis in one piece. He stood at the Berlin Wall, cheered by millions, and it felt as if World War II had never happened. Trump gives the back of his hand to our traditional allies, including those who marched with us into battles around the globe.

Kennedy looked to the heavens and told us we could put men out there. His dreams helped put us on the moon. Trump’s actions, and his words, take us to the gutter. He divides us because he believes it suits him politically. The emotional damage he does concerns him not even slightly.

It’s 55 years since the gun shots in Dallas, but we lost more than a president that awful day. We lost the image of our better selves. Trump takes us to the other extreme. He’s that face in our national mirror barking, sneering, lying, dividing.

A former Baltimore Sun columnist and WJZ-TV commentator, Michael Olesker is the author of six books. His most recent book, “Front Stoops in the Fifties: Baltimore Legends Come of Age,” published by the Johns Hopkins University Press, is now in paperback.