This game (Secret Hitler) ruined quite of few nights when I was an exchange student: people kept playing it while it was limited to only 10 players IIRC and was an obvious albeit less-fun rip off of the game "Les Loups-garous de Thiercelieux"[1].
If Secret Hitler is a ripoff of anything, it's Avalon, which is similar to Mafia/Werewolf, but is much deeper and lacks the issue of player elimination.
I'd say it draws more from The Resistance/Avalon Resistance than Werewolf, since it focuses on voting and scoring points more than killing players and eliminating them from the game.
[1] https://en.wikipedia.org/wiki/The_Werewolves_of_Millers_Holl...