I have heard two largely opposing schools of thought regarding Hitler's rise to power. There seems to be those who claim he was a democratically elected leader, revered by the people and rising to power as a result of that. Others say that Hitler was able to rise to power in Germany largely due to acts of thuggery on the part of the Nazis - things like intimidating the supporters of other parties, and intimidating the leaders of the parties themselves, as well as intimidating average German citizens.
My question is: which of these two schools is more correct, and why? Historical sources for further research are strongly preferred.
On a related note, to what degree was the Reichstag fire used to create support for Hitler taking absolute control? That is, was it used as a political justification for Hitler to take advantage of existing support, or was support of the Nazis directly increased by it?
This is something I do not know very much about, but I do know the knowledge of the concentration camps were kept secret from the German public for quite a while during the war. I have heard Jewish and gypsy POWs would scribble notes and throw them out of the train that was taking them there, but would like to know more if anyone can help about when and how this was brought to light in the general public, and how it affected morale, or other factors in the support of the Nazi regime.