This claim is pretty much Quatsch

This earlier answer of mine tackled a similar line of reasoning:

Beneath the milquetoast paeans to stability and certainty, the linked post is pretty much rubbish. This statement in particular is especially problematic:

Basically, the Nazi party gained power because the Socialists and Communists attacked people on the streets, and the Nazis turned it back on them, destroying the Communists and Socialists again and again and again.

There are a number of problems with this statement.

• Firstly, the author omits one of the important elements in the escalation of street violence: the NSDAP. The SA and other right-wing paramilitaries took to the streets in the crisis years of 1929-33 and they certainly played a major role in the chaos the author laments. The SA in particular was quite violent and to omit them from any narrative is just plain wrong. Much of the SA's actions in the street battles was about asserting control over territory, such as marching in districts that were political strongholds of the KPD, and as such was deliberately provocative. Of the paramilitaries active in these years, the SA was arguably the most "military" with a strong hierarchical structure, uniforms, and martial ethos.

• Neither the SPD nor the KPD were innocent lambs in these years, and both had their own paramilitaries, the main ones being Reichsbanner Schwarz-Rot-Gold and Roter Frontkämpferbund (RFB- note, although banned in 1929, there were various successor organizations and rather than throwing out more acronyms, RFB will stand as a placeholder). Both of these paramilitaries engaged in battles with the SA and between each other and justified their violence as serving ultimate political ends, whether preserving the Republic or carrying forth the workers' revolution. However, to portray them as " attacked people on the streets" is a rather myopic way to view their actions that obscures the very specific context violence on the left often had and makes them out to be thugs accosting non-political Germans on the streets. Street-brawls between factions often had collateral damage for bystanders, but such brawls were typically a consequence of trying to disrupt another groups' rally or defend/reclaim territory perceived to be taken by the enemy. Violence was both real and symbolic, such as stripping insignia or destroying banners, which meant that a hypothetical apolitical German in regular clothes had little signifiers of their political loyalty.

• Both the Reichsbanner and the RFB were also as much at odds with each other in this period as they were with the SA. Lumping them together as the author did loses the very real and important distinctions between the two. The Reichsbanner was caught in a very peculiar bind of being a defender of the Republic, but through extralegal methods. This actually proved detrimental for the Reichsbanner's internal cohesion as it became increasingly unclear what they were fighting for in these street battles. The RFB hemmed and hawed between local activism and wider calls for revolutionary discipline from the KPD leadership. This actually made it rather difficult to parse out what exactly was the RFB's strategy in this period. After the state ban, the RFB briefly abandoned its strategy of confrontation against fascist and cell-based organization and sought to recruit among elements in the SA as part of "organized mass struggle," leading to a brief period of strange political bedfellows between the SA and RFB. This move was unpopular among the rank and file of KPD activists and violence continued at the local level despite moments of seeming cooperation like the 1932 Berlin transportation strike.

The Nazis largely gained power by bringing violence and stability where the police had been ineffective.

• This statement is a bit of a half-truth, but it obscures an important facet of German policing. The Republic's police forces were increasingly impotent to stop the street battles, and this did undermine the popularity of the Republic for some Germans. However, the German police force was not a neutral, apolitical force in Weimar. Police leaders were notoriously sympathetic to the right-wing political spectrum and they devoted a considerable effort to bringing down KPD groups. Statistics gathered by the Berlin police for Prussian Ministry of Interior over police intervention in political assemblies in 1931 shows the police disproportionately targeted KPD assemblies. Such a tilt against the KPD and the left was typical for Weimar law enforcement and extended into the judicial system; Hitler's Beer Hall Putsch ended with a slap on the wrist for the conspirators even though they committed treason. Left-wing offenders did not receive this mercy from the Weimar justice system. The Weimar police, especially in Berlin, was decidedly in favor the German right. A lot of the recent research into street-fighting has shown it is clear that the NSDAP and SA had various covert and semi-covert linkages with the police. The idea that the police and courts were "blind in the right eye" was something known at the time. Weimar judges would be more lenient towards right-wing offenders while tending to throw the book at politically-motivated crimes committed by left-wing defendants. The state dragged its feet when it came to banning the SA, but had no such reluctance for their earlier ban of the KPD's Rote Fahne. All of this meant that the SA possessed a degree of political cover for their violent and often blatant provocations in the the streets. The SA could provoke violence with relative autonomy while the KPD and the SPD's paramilitaries did not have the same luxury. While some within Berlin's police leadership did consider the SA to be uncouth and coarse, this leeriness did not extend to outright hostility to the SA. This gave the NSDAP the freedom to escalate the political chaos in the streets without any real or immediate consequences. SA marches were not innocuous gatherings, but attempts to claim turf and provoke a response. In short, Nazi marches were inherently violent. Counter-violence might have been unproductive, but non-violent opposition on the streets was not really an option when the SA could use their truncheons with relative impunity. Hitler and his cronies had every political incentive to encourage street violence and did so. Not placing the NSDAP as an active political force and instigator in the street violence is a crucial oversight, especially since after Hitler's seizure of power, the police, along with the NSDAP, proved to be quite ruthless in stamping out left-wing paramilitaries.

The fact that you have trouble understanding that the Nazis didn't come to power because you think the Leftists didn't do enough to oppose them, only dooms you to repeating the same mistakes that let the Nazis come to power in the first place.

• The right-wing sympathies of the German police were also mirrored in various elements of the German political establishment. Although the NSDAP had considerable, and in many cases, unprecedented, success in the polls, Hitler had the benefit of a right-wing cabal that actively sought to undermine the Republic. Electoral success, again, is only part of the picture, and counterfactuals in which Hitler loses at the polls for whatever reason have to take into account that the increasingly senile Hindenburg had a conservative camarilla surrounding him that had little love for either the Republic or democracy.

One has to understand that the Nazis were considered the political and economic saviors of Germany. Their social and foreign policies were controversial even at the time.

• This statement is somewhat oversimplified and that oversimplification obscures a lot on the historical nature of the NSDAP's popularity. One of the strengths the NSDAP had both in the seizure of power and its rule over Germany was its ideological platform was often incredibly hazy and quite contradictory. This allowed itself to graft onto existing ideas, institutions, and mentalities within German society. For example, the phrase Volksgemeinschaft which became ubiquitous during the Third Reich was one of the favorite catchphrases of the great SPD leader and one of the founders of the Republic, Friedrich Ebert. Some ideas were indeed controversial, but they also found resonance among a broad swath of German society. This growth in support alarmed many within the Republic, whether among conservatives like the DNVP or left-wing parties like the SPD and KPD. Both Hitler and the NSDAP were not the only political actors promising the German people that they were the saviors from political paralysis of 1929-33 and economic dislocation caused by the Depression. The late Weimar period saw a renewal of this type of millenarian form of politics; returning Germany to stability was only one plank in the NSDAP's platform and its political discourse often stressed law and order as an integral component of the new order. One of the important questions for historians of modern Germany is why the NSDAP managed to succeed here when other parties failed.