I would like to have/find some advice about a legal situation for that possible happening :
Reichspresidential election in Germany 1932. Upt to and going of the first ballot as OTL.
BUT ...
Sometime between 31.March and 5.April Hindenburg dies of natural causes (he was old enough to do soo).
And now ?
Would it have been legally possible for the SPD to announce an own candidate for the second ballot
ALONG
with the DNVP/DVP/Zentrum and other conservatives presenting a replacement for Hindenburg ?
So that there would have been four candidates for the second ballot ?
(i.e. : Hitler (NSDAP), Otto Braun (SPD ... DStP, Zentrum ?, BVP ?), Ernst Thälmann (KPD), Lettow-Vorbeck (DNVP, Stahlhelm, BVP ? , just to name some possibilities)
At the Reichspresidential election in 1925 Hindenburg was - newly - introduced to the ballot race as a "replacement" for Jarres but on the same ... lets call it election platform the "Reichsblock" supported by DNVP, DVP and some other non-party "pressure groups".
The election platform the "Volksblock" was supported by Zentrum, DDP, and now also SPD and settled with Wilhelm Marx as their common candidate.
So : in 1932 would the ... pro-Weimar (more or leas) or better anti-Hitler parties beside the Communists have to settle on another common candidate or would it have been possible to introduce a new candidate on a new election platform ?