One of the really basic mistakes that a lot of people make about Nazi Germany is failing to understand that in many ways, it was a collection of competitive fiefdoms jockeying for power under Hitler. Goebbels's clubfoot was a disadvantage for him in that it was a good basis for disparaging gossip by his rivals--but had he not had a clubfoot, they would have invented something else. Goebbels, like Himmler, Goering, the Rohm brothers early on, and many other examples, had his own power base and his own usefulness to Hitler. Basically, once you get into the top echelon of the leaders of Nazi factions, ideology only counted for so much. If Goebbels had been a young man trying to rise in the ranks of the party once they had come to power, he very well might have found his way blocked by Nazi attitudes towards his disability, but by the time those attitudes were official policy, he was above being directly affected by them.