We know that Dumbledore and Grindelwald theorized about Wizard supremacy over Muggles, and that later Grindelwald was focused on world domination. My question is, what would he have thought about Muggleborns? There is nothing to say that Voldemort and Grindelwald were similar - would Grindelwald have been obsessed with blood purity and the eradication of Muggles and Muggleborns too? Or did he simply want to rule the world? If Gellert Grindelwald had somehow managed to kill Dumbledore in 1945 instead of being imprisoned by the latter, what would the world have been like later on? Would Grindelwald have allowed Muggleborns to attend Hogwarts?