New theory: Voldemort is Dumbledore.
I mean think about it - have you seen the two together in the same room?
McGonagall claims to have. But guess who Minerva spends the most amount of time with in a completely sealed room? Why, Albus Dumbledore.
Why bother with two wizards of immense power and ancient lore, when one could easily fit the information? You might say, "but Voldemort and Dumbledore fought on opposite sides of the war!" Voldemort and "Monroe" fought on opposite sides of the war. It's hardly out of the question.
Consider Moody's claim. "...after Monroe disappeared and Regulus Black... Albus bloody Dumbledore himself had to step into Monroe's shoes, and that was barely enough for us to survive." Why not step in during or before Monroe presented himself? To advance his plans.
We already know Dumbledore is a questionable character with dubious goals. Draco claims that Dumbledore's trying to take over everything, that he's a cold blooded murder, that Grindelwald was merely a pawn of his, and that he was evil from childhood. What evidence have we found to contradict this? He refuses to comment on Narcissa's death, knowingly condemned Hermione to Azkaban, and set fire to a chicken.
He even says to McGonagall that he might be the Dark Lord Harry has to grow to defeat. Might be? He most certainly is! But there's no reason to let his pawn the Transfiguration Professor know that, besides have her implicitly reject the thought from her mind to reassure her unknown master.
James and Lily were members of the Order of the Phoenix, and certainly could have defied Dumbledore thrice each, in varying and light circumstances. Even if not, they certainly defied Lord Voldemort thrice, and Lord Voldemort is Dumbledore's alter ego. We know that Voldemort is a playwright capable of containing many characters - indeed it is known that Voldemort is one of said characters. But everything must have a source, and there must be an original character. Albus Percival Wulfric Brian Dumbledore.
Take a step back and look at what ended happening from the plots. A great and terrible war was spurred by Dumbledore's childhood friend and lover, Gellert Grindelwald, and in the aftermath Albus Dumbledore became the Chief Warlock, the Supreme Mugwump and Headmaster of Hogwarts. Then as his power waned in time, a newer and yet greater Dark Lord arose in the name of Voldemort - upon which he was defeated, and Lucius Malfoy and Dumbledore came to be the two rulers of Wizarding Britain. Lucius Malfoy, the pawn of Lord Voldemort, who is Albus Dumbledore.
Draco was right along. It was right there before our eyes. It was always Dumbledore.