Mellon was a real person - a highly successful banker - who served as Treasury Secretary under Harding, Coolidge, and Hoover, the three Republican Presidents who brought us the Roaring 20s and then the Stock Market Crash and the Great Depression. Mellon was only one of three people to serve in the Cabinet for three successful Presidents (see Wikipedia for details), and his policy of drastically lowering taxes, but in a progressive way that had lower income earners paying far less a percentage of their earnings than the rich, had a powerful and beneficial impact on at least the first part of the 1920s.
Mellon's opposition to federal spending to combat the Great Depression - reversed by FDR - made Mellon unpopular. Impeachment charges were considered against him, and, according to Boardwalk Empire, he also had a revealing conversation with Nucky Thompson.
Nucky saw Mellon as a great weapon in Nucky's attempt to retaliate against Attorney General Harry Daugherty. Although Mellon is arch and even contemptuous of Nucky, the Atlantic City "gangster" (Billie's endearing term for Nucky) manages to enlist Mellon against Daugherty, mostly by showing Mellon how we could make money from booze. It's a revealing moment, and epitomizes what is in effect is the credo of Boardwalk Empire: booze conquers all.
One of the best things about Boardwalk Empire, especially this season, is the ground it covers, from joints in Chicago and Atlantic City to Broadway stages and movie-making in New York, to smoke-filled rooms in the seat of power in Washington. And all with an eye to current events of the 1920s which still figure prominently today, whether control of women's bodies or taxes. I would have voted Democratic back then and I will tomorrow. And I'll look forward to see how the battle continues to play out on Boardwalk Empire next week.
See also Boardwalk Empire 3.1: Happy News Year 1923 ... Boardwalk Empire 3.2: Gasoline and the White Rock Girl ... Boardwalk Empire 3.3: The Showgirl and The Psycho ... Boardwalk Empire 3.5: "10 L'Chaim" ... Boardwalk Empire 3.7: Deadly Gillian
And see also Boardwalk Emipre on HBO ... Boardwalk Empire 1.2: Lines and Centers Power ...Boardwalk Empire 1.10: Arnold Rothstein, Media Theorist ... Season One Finale of Boardwalk Empire