It's something of a cliché that the Nazis rose to power, at least in part, due to the fear of Communism which lead to many people supporting them as a bulwark against revolution. Certainly on a geopolitical level this is true as many supported appeasement as a means of creating a counterweight to the USSR. By extension it is commonly held that, without the Bolshevik Revolution, the Nazis wouldn't have come to power.
I would argue, however, that even in the face of a failed or stillborn Bolshevik Revolution there is still a good chance that the Nazis could still come to power. The main reason for this is that without the Bolshevik Revolution the Socialist and Social Democratic parties of Europe would be more unified and larger, due to them not experiencing the splits that occurred with the establishment of the 3rd International, and would still retain the radicals who IOTL formed the various Communist parties. Should those radicals within those parties succeed in gaining influence over the membership and party machinery, say in the aftermath of the Great Depression, it seems to me that the powers-that-be would find that a pretty terrifying prospect and might be willing to, grudgingly, throw their support behind fascists and other far-right political movements to keep them from taking power.
Another factor that could, depending on how things play out, affect the rise of Fascism in Germany is how the absence of the Bolshevik Revolution plays out in Eastern Europe, particularly Russia and Poland. Whilst there are too many variables to list all the possible outcomes I personally think that it's still likely that Russia could face some sort of civil war, due to the various separatist movements in the Russian Empire and the weakness of the Provisional Government. The aftermath of such a war could easily result in a militarised and reunified Russian Empire or possibly the success of the Intermarium project, which depended on weakening Germany and Russia, either of which could present the Nazis with a ready Slavic Hordes narrative.
Another factor to consider with regards to a Russian civil war without a prior Bolshevik revolution is that the Weimar government, dominated by the SPD in its early years, might be open to allowing political dissidents and refugees fleeing from the war to settle in Germany, which would provide the Nazis with amply "evidence" that the SPD were in league with dangerous radicals and wanted to flood Germany with Jews and Slavs.
In addition, the various other factors that served the Nazis and far-right in Germany would likely still be in effect without the Bolshevik Revolution: the stab-in-the-back myth, the humiliation of the Treaty of Versailles, widespread and latent antisemitism, an anti-democratic conservative establishment in the judiciary, military and civil service and the Great Depression.
I would argue, however, that even in the face of a failed or stillborn Bolshevik Revolution there is still a good chance that the Nazis could still come to power. The main reason for this is that without the Bolshevik Revolution the Socialist and Social Democratic parties of Europe would be more unified and larger, due to them not experiencing the splits that occurred with the establishment of the 3rd International, and would still retain the radicals who IOTL formed the various Communist parties. Should those radicals within those parties succeed in gaining influence over the membership and party machinery, say in the aftermath of the Great Depression, it seems to me that the powers-that-be would find that a pretty terrifying prospect and might be willing to, grudgingly, throw their support behind fascists and other far-right political movements to keep them from taking power.
Another factor that could, depending on how things play out, affect the rise of Fascism in Germany is how the absence of the Bolshevik Revolution plays out in Eastern Europe, particularly Russia and Poland. Whilst there are too many variables to list all the possible outcomes I personally think that it's still likely that Russia could face some sort of civil war, due to the various separatist movements in the Russian Empire and the weakness of the Provisional Government. The aftermath of such a war could easily result in a militarised and reunified Russian Empire or possibly the success of the Intermarium project, which depended on weakening Germany and Russia, either of which could present the Nazis with a ready Slavic Hordes narrative.
Another factor to consider with regards to a Russian civil war without a prior Bolshevik revolution is that the Weimar government, dominated by the SPD in its early years, might be open to allowing political dissidents and refugees fleeing from the war to settle in Germany, which would provide the Nazis with amply "evidence" that the SPD were in league with dangerous radicals and wanted to flood Germany with Jews and Slavs.
In addition, the various other factors that served the Nazis and far-right in Germany would likely still be in effect without the Bolshevik Revolution: the stab-in-the-back myth, the humiliation of the Treaty of Versailles, widespread and latent antisemitism, an anti-democratic conservative establishment in the judiciary, military and civil service and the Great Depression.