Some people just plain dislike former New York City Mayor Rudy Giuliani. Others, like Ed Koch -- who was himself mayor of NYC -- hate Giuliani with a fiery passion. Koch is the author of "Giuliani: Nasty Man," and he writes frequent commentaries and movie reviews that he e-mails out to various friends and acquaintances. Here's how he begins his latest commentary:

As I watched Rudy Giuliani deliver his keynote speech at the Republican National convention last week, I noticed a verbal tic intruding into the former mayor's hatcheting performance. It was a kind of maniacal laugh appearing before or simultaneously surfacing as he delivered his slashing attack on Senator Obama.

As I watched, I knew I had seen that laugh before. Suddenly I knew, as my brain finished its card sorting of the stored recollections within my skull and came up with the memory I sought. There was the picture of actor Richard Widmark, now deceased, carrying out his role in the movie "Kiss of Death." I saw once again the scene in which Widmark, playing Tommy Udo, a killer, pushed a wheelchair in which an old woman was sitting and, laughing maniacally, shoved it off the top of the stairs with its occupant still in it.

Someone -- a friend of Rudy's -- should draw his attention to this mannerism so that he can seek to eliminate it before he runs for public office again, maybe mayor, maybe governor.

Though it was originally released in 1947, because of the wonder that is YouTube, you can watch the scene that Koch describes below. The key part starts about two minutes in.