For the once caring or interested in history:
Historically the time around 1848 was signed by revolutions all over Europe because of the lately upcoming idea of nation and the attempt of the lower class (in most cases) to break free from the chains of monarchy, absolutism and other forms of elite-exclusive ruling.
The desire for a constitution caused uprisings and to prevent them to spread most rulers established parliaments to calm the masses. The Frankfurt parliament was one of those. As to say, its greatest weakness was that it was still dependent on the monarchs of Prussia (or the ones of Austria) for it had no own army to enforce rights and defend the people. Additionally the Frankfurt Parliament was deeply split inside itself, as the parties in the parliament were focussing extremely different aims, consisting of ultra-right wing (conservatives) to ultra-liberals and (at that time only few and radical) democrats, resulting in political inability to act as one. Whats interesting about this, is that mostly it consisted of very well educated people.
When then the July crisis in Schleswig emerged the Prussian monarch took his chance and dubbed the Parliament in an elegant way. As it was obvious then, that the Parliament was relying on help from "the outside" to act, he showed all, that it was unable to act and etablished a peace treaty with (i think it was already called like that then) Denmark without consulting the Frankfurt Parliament, and by doing so demonstrated their lack of power, discrediting them publically. This resulted in the desolving of the Parliament as it was shown to be not functioning. By the way, as a fun fact: The King of Prussia was offered the crown (of "Germany" - this would be the so called "kleindeutsche Lösung") before, but he refused.
But although as the Frankfurt Parliament resulted in a catastrophe, the desire for a Parliament got stronger and stonger. As you might now, by the end of the 19th century in Germany the Kaiserreich under Bismarck as chancellor was established, then playing a major role in politics. So the idea of constitution won in the long term (obviously at least today, as there are only a few monarchies left - and most of them only representative).
So far. If anyone can correct me, feel free to. This is what I remember by heart of that time, so maybe there are slight mistakes. And of course this is non-scientific. But if you are interested, I can give you some pointers for literature in which you can read about it.
Greetings
fderk