Robert De Niro in this film

De Niro would feel a little too rough and streetwise for the Blake role.

I just can't see anyone else playing Blake other than Baldwin. He was so good-looking back then, and his voice is so seductive and smooth, yet menacing. It's masterful casting...a real silver-tongued devil.

De Niro could probably have been a good Moss, but then again Ed Harris was perfect.

I can see De Niro as any of the guys--even Aaranow--except Levine. And Williamson of course.

He definitely would have been great as either Blake, Roma, or Moss.

I read in the IMDB trivia that De Niro was interested in playing Levine. I honestly think he could have pulled it off, De Niro has played some flawed/weak characters before. IIRC, he and Bill Murray actually intentionally switched roles in Mad Dog & Glory, with Murray playing the heavy and De Niro playing the meek character. Night and the City, too, De Niro plays kind of an incompetent character in over his head.

Ironically or not, both films were released around the time of Glengarry, so maybe DeNiro was on a tear of trying to break some tough guy stereotype.

He would have been an interesting version of Levine, but man, Jack Lemmon was *good* and has such an awesome sales voice, too.

I suspect he was another option for Roma, assuming that the filmmakers couldn't land Al Pacino. Tempermentally, I could also see him as the aggressive, brooding, embittered Moss.