There a easy POD how Hitler could loose the 1932 election
Goebbels wrote in his diary year 1930, that he wanted to OUIT the NSDAP !
He was disappointed about the opportunistic fraction in Party, Intrigue against him by high rang members like Himmler and lack of leadership of Hitler over the Party in this time
without Goebbels, Hitler had focus more on Munich, instead the capitol Berlin
also not used the Aircraft for his election campaign, only Car and Train.
next to that Hitler miss with Goebbels a talented writer/good speaker for the NSDAP public speechs
My guess is if Goebbels Ouit's the NSDAP he take his parliament seat (won under NSDAP in 1928) and
join the DNVP (German National People's Party)
the main nationalist party in Weimar Fepublic composed of nationalists, reactionary monarchists, völkisch, and antisemitic elements, and supported by the Pan-German League.
OTL the DNVP had formed an uneasy alliance with NSDAP and the Stahlhelm paramilitary organisation during 1931
were the NSDAP make profit, by get money and members, in 1933 DNVP was absorb by NSDAP
But with Goebbels insider knowledge about real situation in NSDAP, DNVP never allied with them
and the DNVP would get a effective propaganda machine, not the NSDAP...