First off, Otto von Bismarck was still very much a young man during the Revolutions of 1848. Although his political star was on the rise in 1848/49, he lacked the political capital to set policy and make decisions. The young Bismarck was very much a lieutenant of the conservative Prussian camarilla of the Gerlach brothers. This tumultuous period helped establish Bismarck as a Young Turk for Prussian conservatives, but it was not up to this Bismarck to accept or reject the Paulskirche parliament's plan for German unification.

Nonetheless, Bismarck did position himself within the Prussian Landtag as one of the foremost opponents of the Paulskirche unification plan. This was in keeping with the larger opposition of Prussian conservatives to the broader political agenda of the various political ideals that found a home in the fractious Paulskirche parliament. Even though Bismarck would later champion unification of Germany on behalf of both the Hohenzollerns and the Prussian right wing, this was not a case of the Prussian Junkers co-opting an earlier liberal agenda. Both in form and execution, the plans for national unification were quite different in 1848 than they were in 1871.

One crucial difference between the two drives to unification was that the Paulskirche delegates were pushing for unification of Germany that would possibly incorporate a Großdeutsche of both Bohemian and Austrian lands. Many of the Paulskirche delegate had backed away from the extremes of this position over the course of 1848, the proposed constitutional order still allowed for the possibility of incorporating these areas into a German state in the future. This was something Bismarck appreciated as both impractical from a Realpolitik perspective as well as for confessional reasons. Although Bismarck would often rewrite history to suggest he was more sagacious and far-seeing than he was in reality, he did appreciate the potential problems of creating a German state that was too large. Disposing of the Habsburgs would have opened up the question of what happens to the non-German parts of their domains, which in turn invites the interests of the other European powers. Bismarck went to great lengths during the Austro-Prussian War to dissuade the army and his sovereign Wilhelm I from pursuing a Carthaginian peace. At one point, Bismarck actually threatened resignation and then suicide if Wilhelm I went through with demanding a more severe peace at a meeting with the King at Nikolsburg in July 1866. The Paulskirche constitution and its liberal champions tended not to appreciate the diplomatic balance of power that would result from German unification.

The open question of what borders a German state would take underscores two other broad differences in the approach to German national unification. One issue was that the proposed constitution generally provided for equality between all existing German states in a federal union. This in some way presaged the type of federal union that Bismarck sponsored in 1871, but there were some crucial differences. For one thing, the constitution was very much a liberal document with balance of powers and rationally-divided order predicated on the rule of law. The former was anathema to many Prussian conservatives including Bismarck. The constitutional order Bismarck created did have elements of the earlier Frankfurt constitution such as a nationally-elected assembly, but it also had various triggers designed to guarantee the strength of the traditional aristocracy and monarchy. This was clear in the comparison between the upper parliamentary chambers. The appointed delegates of the Bismarckian Bundesrat was intended as a firebreak against the Reichstag gaining too much power and it was designed to give more weight to Prussia. The Frankfurt Staatenhaus was a much more democratic upper chamber with deputies coming from both appointment by the Land governments and their parliamentary bodies.

The Prussian King Wilhelm IV famously declined the offer of a German crown by claiming it came from the gutter. This harsh dismissal by the eccentric Hohenzollern underscores not only the low esteem German monarchs had for the Paulskirche parliament, but also the differing views on the nature of national sovereignty. In the case of the Paulskirche, national leadership was a gift of the German people via their delegates to a Prussian sovereign. Bismarck would reverse this calculus during the drive to unify the country by portraying unification as a gift of the sovereign to the German nation. National sovereignty, instead of flowing from the people, originated from the monarchy. The constitution was not a sacred document in Bismarck's political Weltanscahuung reflecting the general will, but an endowment that the monarch gave to his people.

Even here Bismarck encountered friction from his own master, Wilhelm I and the other aspects of the German conservative establishment. The idea that a sovereign needed a political document like a constitution to validate their rule was antithetical to some reactionary circles as an undue restraint on the exercise of political power. Wilhelm I had to be cajoled and flattered into accepting the title of Emperor especially after Bismarck was able to engineer it to appear to be a gift of Wilhelm I's fellow German sovereigns.

It certainly did not help the Paulskirche parliament's case that the political tides had clearly shifted against the revolution by 1849. But the proposed unification plans bandied about at Frankfurt had very few allies outside of liberal circles within Germany. Prussian conservatives like Bismarck perceived that the proposed unification would weaken both Prussia as well as the political strength of the Junkers aristocracy. Bismarck was canny enough to appreciate some of the merits of the Paulskirche proposals such as a nationally-elected parliamentary body, but he and other Prussian conservatives wanted German unification on their own terms.