Hindenburg could avoid appointing Hitler for a while, but with his electoral strength, it was going to be very hard to keep him out for much longer.
Minority governments had been in place since 1930.
Thus, I beg to differ. Not accepting the electoral success of the NSDAP was part of the strategy of discrediting parliamentary rule and to move the Weimar Republic into a Presidential/Authoritarian/Restaurative direction. All parties, including the Nazis, should exhaust themselves financially in campaigning, mentally in fruitless debates in the Reichstag, and in quarrels in the streets.
The "opposition"-argument does not fully work here, at the latest after Brüning's demise most parties where opposition parties. Some of the parties closest to the presidential governments where actually rather stable: the reactionary DNVP which supported von Papen remained stable at 6-8% in 1930-33. The Centrum, of which both Papen and Brüning were members remained between 11.3 and 12.5 during the four elections of 1930-33.
It's hard to see the Nazis disappearing until they held office and failed, or tried to take power by force.
They wouldn't go that quickly, but they had reached an electoral ceiling in 1932 (which can somewhat be proven by the disappointing result of 43.9% in March '33 when even massive inhibitions, manipulations and propaganda effort plus the "achievements" of their first weeks in power failed to bring them a majority on their own).
It is hard to imagine a government that bad that unemployment wouldn't fall in 1933. In fact, part of the programmes started in 1933 where in preparation beforehands. Even if unemployment falls less rapidly than OTL, it would drain the NS-appeal. Then there is the end of reparations.
Also, politically, the NSDAP was a rather destructive force. This may work attractively for a while in times of despair. But long range? German election results prior to 1932 and after 1945 give little indication that such an extremist party would attract more than 20% of the voters in the long run.
It would be interesting, though, what developments the NSDAP would undergo in such a situation.
If there is again another election say in summer of 1933, with unemployment having sunk by a million since winter - I can see the NSDAP continue the slow decline which marked the november-elections. Maybe they go down to 31%. Even remaining the strongest power in a powerless Reichstag, the signal would be seen that they were a frantic movement which had passed its zenith.
If Hitler had any sense, he would just wait Hindenburg out. If he tried to seize power by force, he could be defeated if the army stuck with Hindenburg. The Nazi party could then be banned and their earlier electoral gains would count for nothing.
If provocing a Civil War would have promised success, Hitler might well have tried. It is not as if the Nazis were shy of killing Germans. But sitting Hindenburg out...after November '33 it rather seemed to be now or never.
A French occupation of the Rhineland would be perilous, casting France as the bad guy and creating sympathy for the Germans. Since France was headed for disaster in 1940 anyway, though, I can't say that it would necessarily have been any worse in the long run.
I agree, though, with you and most recent contributors, that the risks in French intervention outweigh the possible gains and that Paris was most probably aware of that.
P.S. If anyone mentions Lippe, one should mention the insane campaigning which went on there as well and bear in mind that this land had only a little more than 100,000 voters.
