Okay … I’m imagining Dr. Eckenburg straffing Nazi Party HQ from a Graf Zeppelin upgraded with machine-gun mounts. It’s a pleasant image, but perhaps not terribly realistic.
Short of that, what could Eckenburg have done to keep Hitler out of power once the Nazis started winning elections? My understanding that was the Presidency of the Weimar republic was fairly weak. Am I mistaken?
You are. It was the Office of the Chancellor that was weak. The President had the power to appoint the Cabinet, the President had the power to dismiss the Reichstag and call for new elections, the President commanded the armed forces, and, if in the opinion of the President, there was a “threat to public order or security”, he could rule by decree and suspend civil rights.
So, theoretically, he could have declared that the Nazis represented such a threat, he could have invoked the emergency decree, banned the party, and arrested leading Nazis and held them indefinitely without trial.
Thanks, Captain Amazing. Consider ignorance fought!
So, if Hindenburg had all this power, why’d he let Hitler grab it?
He was an octogenarian, was in very poor health, and going senile. Toward the end he kept mistaking Hitler for the Kaiser and calling “Your Majesty”.
Surely you jest. 
I hadn’t heard that one. But Hindenburg’s son, who was not senile, is on record that before Alzheimer’s set in, Hindenburg was very opposed to Hitler. But after he lost it mentally, he was very confused as to Hitler was and what he stood for, and Hitler knew how to play that up and gain his confidence. Result: he named Hitler Reichskanzler, and the rest is, sadly, history.