You could call this ASB, but I think stranger things have happened in the past.
Let us suppose that, following the failure of Citadel in 43, Hitler believes that defeating Russia has become a near impossible task. He feels therefore, for whatever reason, that German lives need no longer be lost in fighting the Soviet Horde when the victory he has sought for so long has become impossible. He approaches both the Allies and Soviets in an attempt broker an honourable peace, but they all, by this point, refuse to consider a conditional peace with Nazi Germany, especially after the soviets have delivered such a devastating blow against them.
Going against everything that Nazi ideals stand for, and in seemingly a complete turnaround, Hitler decides to announce that he will be stepping down as Fuhrer, and that the position will be abolished (reverting back to President and Chancellor), following a general election, which he has called to take place within 3 months. Importantly, he claims that this will be a multi-party election, with previously banned parties, including communists, allowed to stand candidates, and a number of key political prisoners will also be released to show sincerity in this matter. Anyone with German citizenship may vote. Any violent tactics by parties (including his own) to intimidate voters will be banned again. Furthermore, he announces the arrest of a large number of key Nazis (Himmler, Bormann and Goering included) for "Crimes against the state; allocating war resources for personal interests; corruption; and for jeopardising the fairness of the upcoming elections). He stresses that he is making this personal sacrifice to save the honour of the German Reich, and to prevent the world from being 'conned' into believing the lies of Stalin and the Soviet Union.
Assuming Hitler is true to his word, and fair multi-party elections take place. Who wins, and what happens in the long run for this new government, Germany, and the world? How will the world react, and how will Nazis, amongst others, react and treat these elections? Could die hard Nazis be able to prevent this election from happening in the first place, deposing their once beloved Fuhrer, for the sake of the Reich?