These 50-year commemorations keep sneaking up on me.

One of them, Aug. 29, 1968, occurred in Grant Park, Chicago, during that year’s Democratic National Presidential Nominating Convention.

Democrats nominated Vice President Hubert Humphrey to run against Republican nominee Richard Nixon. Humphrey lost the election narrowly to Nixon.

HHH’s political fate likely was sealed in Grant Park, when Chicago police applied brute force to put down a riot being staged by hippies, Yippies and assorted other anti-Vietnam War protesters. It was an ugly night of violence.

I was about a week into my own duty in the Army. I would head to Vietnam the following spring. But, oh, I do remember that political year. My first political hero, Sen. Robert Kennedy, was gunned down in the Los Angeles hotel kitchen after winning the California Democratic presidential primary. RFK’s death came two months and a day after the Rev. Martin Luther King Jr. was shot to death at the Lorraine Motel in Memphis, Tenn.

I want to take particular note here to remind us that no matter how divided we are today, it could actually be worse. The Grant Park riot 50 years ago today tells me just how deep and wide the chasm can get.

I do fear that we might be headed in that direction five decades later. If we get there, then we’d all better prepare for the worst.