In other words, in the 30ies when Hitler was rising, was he the bad person we percieve him today, or did he turn into that as he was in power (podsibly because of the power)? I know in hindsight he is often portraied as a psychopath and made to look psychopathic all his life. The background of my question is: many recent political figures are compared to hitler every now and then (in russia, europe and the US). i wonder if hitler knew he was hitler?
Hitler adopted the principles that he is known for well before the 30s. He wrote Mein Kampf in 1923, which advocated State use of propaganda, defending "against the Jews" and the desire for expansion to the East. Mein Kampf was essentially the foundation for the actions he took while ruler of Germany. Certain specifics (such as how to deal with 'the Jewish problem') were not fully decided until later, but it can be said fairly comfortably that Hitler knew the actions he would take if he came to power.
ps. Mein Kampf is available free online, in English, at many sources. It's a fascinating read if you're interested in Hitler's mindset.