Well, the Bismarckian constitution was a byproduct of the Iron Chancellor and his age. This meant it provided a constitutional monarchy with a strong emphasis upon the monarch. The Kaiser in the constitution possessed a good deal of authority with regards to the central government (eg the chancellery, ministers, etc.) and war-making. The constitution also provided for an upper chamber, the Bundesrat, which Germany's various princes and kings sent their personal delegates. The 1871 constitution also granted Bavaria, Saxony, and Württemberg their own war ministries and armies which they governed in peacetime. This reflected some of the compromised nature of 1871 document where Bismarck sought to co-opt German particularism in the name of a Prussian-led unification. Likewise, the universal suffrage for the Reichstag granted by the constitution proved to have unintended consequences. Even though Bismarck did not really want to embolden parliamentarianism- Article 21 of the constitution forbid deputies from drawing a salary- the granting universal suffrage and the powers of the Reichstag over the budget led to the emergence of mass party politics within imperial Germany.

This brief sketch of the Bismarckian constitution illustrates how it was a constitution that was somewhat clunky and designed for a monarchical system of government. In short, it was not suitable for the conditions in which Germany found itself in November 1918. The sudden collapse of the Kaiser's political position damaged monarchy in Germany considerably. The parliamentary wing of German politics had been increasingly upset prior to 1914 over their being locked out of political power and the looming defeat in late 1918 emboldened the Reichstag's deputies to take over the situation. Wilhelm II's dithering meant that transitioning to a more equitable power-sharing arrangement between the Reichstag and the imperial house became impossible. The sailors' mutinies coupled with larger strikes and other disturbances in November 1918 led to a wave of abdications, starting with the Hohenzollerns and followed by the other German royal houses. Without a clear political center, many the Reichstag's chief deputies took it upon themselves to form a new government.

This new government needed a new constitution. The Bismarckian one was unsuited for the situation within Germany in 1918/19. There were no royal houses to appoint to the Bundesrat, nor was there a Kaiser to act as a supreme war lord. Moreover, much of the Reichstag's leadership had become quite disenchanted with the Bismarckian constitution during the decades leading up to the war, and they sought to craft a document that granted greater power to parliamentarianism. The resulting constitution did strengthen the hand of parliament, but were compromises with the Reichstag's right-wing, mainly in granting the Reichsprasident a good deal of emergency powers to function as an ersatz Kaiser. The Weimar convention also reformed the upper chamber, renaming it the Reichsrat, and while its deputies were appointed by their Land's governments, the Reichsrat had a more equitable power-sharing arrangement between the Länder than the old imperial body. The imperial Bundesrat gave disproportionate power to Prussia and the new upper chamber tried to mitigate the power of Prussia by mandating that half of Prussia's delegates come from the provinces while also increasing the number of delegates from the larger German Länder like Bavaria. The constitution also sought to be more democratic and populist than its predecessor by making provisions for plebiscites and referendums.

The long and the short of it was that the Bismarckian constitution was more or less a dead document by November 1918. It was an attempt by Bismarck to strengthen monarchy (or more accurately, the Kaiser's chief minister) via democratic means and it was not a great success. The 1871 constitutional order had created a good deal of internal political conflict by the turn of the century. While some of the Reichstag's deputies and political party leaders were willing to work within the system during peacetime, the war opened up the pre-existing fissures within the German body politic and defeat turned these fissures into an unbridgeable gulf. Most of the German parliamentary faction recognized that the monarchy was a lost cause in 1918 and that trying to preserve it would embolden radicalism such as the USPD, the Spartacus League, and nascent communist parties who might reenact the Russian Revolution within Germany. This fear of left-wing political violences was one of the reasons the convention met within the sleepy town of Weimar; it was feared that it could become hostage to the mob if it were convened in Berlin or some other large city. So it became very urgent for those champions of parliamentarianism within Germany to craft a constitution very quickly in 1918 that restored a sense of order to the country.