Quick victory for the Kaiserreich in the Great War leaves the absolutists and militarists with inflated egos, but also it can perhaps prevent the war from dragging on long enough for the Social Democrats to support it - thus keeping the party from splitting and from the elements that would otherwise have become the Spartakists from being around in a strong-monarchy Germany to be made into examples and squashed in order to discourage future reformists.
With a strong SDP, strong ultra-monarchists, and perhaps no communists or center-rightists of note between (after all, if the Kaiser and the Prussian establishment was so successful, that would pretty much force pro-parliament power conservative parties to break up and either join the Kaiserine establishment or join the established opposition - the SDP) you are set for a showdown that will create a radically different set of social and cultural problems than the ones we associate with a long dragged out World War One (regardless of who loses and who wins).
That is, rather than the disgruntled veterans you get in both the victor and loser countries from the OTL Great War, a quick victory is going to cause the mainstream politics of Europe to be revived with new life, I think.
Instead of communists gaining power and veterans forming fascist groups, you'll have opposition parties that can blame ruling parties for the defeat and not look soiled by it themselves due to the shortness of the war and you'll have ruling parties that are emboldened by the victory and thus push more and more people into mainstream reformist opposition movements rather than the extremist fringe movements that bloomed successfully in the wake of a long and demoralizing war.
Anyway, in the political struggle or civil war between the Reformists and the Absolutists if the Reformists win or if the Absolutist side wins but ends up getting a monarch who likes to reform from above, you can end up with Einstein returning to his country and becoming a famed scientist at a national institute. This could lead to political ambitions.
Einstein as a SDP backbencher who is thrust by circumstances into the Chancellery is interesting, so is Einstein as the man selected by a Maximilian Hapsburg type pro-reform absolutist monarch.