Solution: 25 Characters
Answer: FISCAL DEFICIT

Written by Xue Heng

We should start by identifying the people, most of which shouldn’t be too difficult given the enumerations (for consistency’s sake, the names used are those of the wikipedia articles associated with each person, to avoid confusion with abbreviations, nicknames, birth names etc.). We then extract from each person’s name using the number in brackets as the index.

Doing so and reading the extracted letters in the given order of the clues gives us the clue phrase WHAT’S MISSING FROM EACH CLUE. Next, the strange choice of words and phrasing in many of the clues should arouse our suspicions, and we realize that each clue is a lipogram: it contains twenty-five letters of the alphabet with exactly one letter missing! The answers to the clues and the missing letters are given as follows:

Name Extracted Letter Letter missing from clue
H.G. Wells W O
Henri Rousseau H F
Karl Marx A A
Albert Camus T D
Genghis Khan I J
Buster Keaton S T
Ho Chi Minh M B
Alexander King I I
John Wilkes Booth S S
Caryl Chessman S C
Fanny Brice I O
Ramakhrishna N F
Humphrey Bogart G D
Wolfgang Amadeus Mozart F O
Alan Freed R I
Russ Columbo O C
Anna McNeill Whistler M I
Alexander Graham Bell E S
Edgar Allan Poe A E
Chico Marx C L
Jesus Christ H G
Henry Luce C N
Sholem Aleichem L I
Gunga Din U A
Patrice Lumumba E S

Googling a subset of these names together will lead us to the song “Done Too Soon” by Neil Diamond, which references all twenty-five of these people. Rearranging the missing letters from each clue in order of appearance of these people in the song’s lyrics, we get GOOD JOB ANS IS FISCAL DEFICIT, so we submit FISCAL DEFICIT.

Author's Notes

Having to use all except one particular letter of the alphabet turned out to be more difficult and tedious than I expected, and I did not have an elegant way to clue some of these people, leading to some slightly awkward phrasings. I have a newfound appreciation for Ernest Vincent Wright, the author of Gadsby - a novel which does not contain the letter E.