The story
Coined in 1971 by Boston Globe editor Bill Cardoso. Of uncertain origin; OED proposes Italian gonzo (“dolt”) and / or Spanish ganso (“dolt, goose”). The etymology supplied by Cardoso himself (French gonzeaux) is spurious; French does have a similar word gonze, but this is a loan from Italian.
Etymology from Wiktionary, CC BY-SA 4.0.