WASHINGTON — I've always liked this place.

"Enjoy" is not a word one uses in connection with the U.S. Holocaust Memorial Museum, but I've always found a visit here conducive to contemplation and reflection. So it is even on a fog-shrouded morning when you can't get in, when yellow tape rings off the entrance, police vehicles sit with lights flashing and armed security stands watch.

Last week, a man with a rifle walked in and opened fire, fatally wounding security guard Stephen Johns. Other guards shot the intruder.

Authorities say the shooter, James von Brunn, was an avowed racist and anti-Semite well known to the pustular netherworld of white supremacy and to those who monitor it. He believed the Holocaust a hoax and America a "Third-World racial garbage dump." He believed this, even at 88 years of age. "It's time to kill all the Jews," he wrote in one e-mail. And can you imagine what might have happened had he managed to shoot his way past the guards?

It is jolting to recall that I once thought we were living in the last days of creatures such as this. My only excuse: it was the 1970s and I was young, raised on civil rights marches and Norman Lear comedies. Kids like me felt, with the offhand smugness of youth, that we were harbingers of a new world too enlightened to ever again hate people because they were. We were past all that.

Or so we thought. Because what a shock it is to wake up 40 years later in a world where the intercultural dialogue we thought we'd mastered has become a shrill circus overrun by haters and opportunists, a world where on any given day one might be assaulted by the casual anti-Semitism and homophobia that afflict so much of the African-American community, or the racist patter of a washed-up TV star who has mistaken freedom of speech for freedom from thought, or the gassy posturing of political and media figures who happily, disingenuously trivialize the rawest wounds of the American experience for ratings and political position.

We act as if it were all a game, as if it means nothing when people of position and visibility spew garbage, validating and galvanizing the unhinged and the disaffected who need little encouragement to believe all their problems are caused by Them. We act as if we do not toy with fire when people of authority claim white Christians are a victimized minority or Hispanics a threatening and faceless Other. We act as if we were not heirs and witnesses to a blood-soaked history that tells us exactly where this hate some of us so fecklessly stoke will logically, inevitably lead.

Hate groups standing now at record numbers. One dead. Ten dead. Six million dead.

I've always liked the Holocaust Museum because it is a stark reminder in an era where too many are in a hurry to forget. And so it is even today, even quiet and locked up tight. Behind yellow tape it sits, scene of a hate crime authored by an old man who thought he was great because his skin was pale. An American flag droops limply at half staff as if tired of waiting, waiting for the last days of creatures such as this.