Groups hungry for a strong leader are going to be taken advantage of. That's what the strong leader part is about. </ tangent> He was also offering much more than strong leadership; he pointed enemies, he gave Germany back its army, and he presented himself as the uncorrupt alternative to the inefficient republic of the time.
But had he never linked up with the Nazi party
But he did. I don't see the point in making him seem less dangerous than he was. It seems to me that the more aware we are of how insidious the process of Hitler coming to power was, the more chances we have of stopping another such madman from coming to power - at least in the country we live and/or vote in. (Yeah, I know, my illusions are touching.)