Voldemort is the main villain of the Harry Potter franchise. Harry Potter is that thing your kids won't shut up about.
Lord Voldemort is the Harry Potter franchise's leading douchebag. Sure, there are other douchebags, running the gamut from Archie Bunker-style racial insensitivity to cold-blooded murder. But all other HP-World douches pale in comparison to the smell put forth by the most malodorous of douches, Lord Voldemort, a man so douche-y, that most people refuse to call him by name. Even Hitler was called Hitler.
He started as Tom Marvolo Riddle, and was raised in an orphanage. Punky Brewster, without the boobs.
Through a combination of a fear of death and not-that-subtle hatred of parts of himself, he decided to prey on people's natural prejudices and ignorance to fool them into rallying towards a specific political agenda.