Album:
... And Justice For All

The black list:
The blacklisting took place in the 1950's where everyone whose view was a little out of the ordinary was immediately labeled for beeing a threat to the society - a communist. In Hollywood were a lot of people whose views didn't fit in with the mainstream, so they all were shoved out of the entertainment industry just because of their convictions.

A tribute to Cliff?
If the song would be a kind of tribute to Cliff it would refer to the irony of Cliff's death. Every band member had his own seat in the tour bus - except in the tragic night in which Cliff did swap his seat with Kirk because they made a kind of game about it and Kirk pulled the right card ("spade ace"). So in that way Cliff picked "The Shortest Straw" before the terrible accident in 1986.
- but wouldn't be that sort of tribute a bit too sarcastic?

The subject matter:
It deals with the blacklisting as a whole.