Looking at the broader global pattern over time, we see that parties are often formed for a quite specific reason or set of reasons, but that they gradually lose focus over the years.
The Republican Party in the United States, for example, was formed for the sole purpose of eliminating slavery. It has, in the intervening century, expanding its concerns to economics and foreign policy.
In addition to losing a specific emphasis over the decades, parties also lose consistency.
The reader will note that on any specific question, there is a diversity of views within almost every party.
As parties lose focus and consistency, they gain a different goal. The goal of nearly any political party eventually becomes that of obtaining, maintaining, and retaining power.
Parties begin by using parliamentary maneuvers to achieve their policy goals; they end by using those maneuvers to keep themselves in power.
Friedrich Nietzsche observed that there is an inevitable tendency to deceive in partisan politics; note that he writes, not that a party member ‘is’ a liar, but that a party member ‘becomes’ a liar:
By lie I mean: wishing not to see something that one does see; wishing not to see something as one sees it. Whether the lie takes place before witnesses or without witnesses does not matter. The most common lie is that with which one lies to oneself; lying to others is relatively, an exception.
Now this wishing-not-to see what one does see, this wishing-not-to-see as one sees is almost the first condition for all who are party in any sense: of necessity, the party man becomes a liar.
Although there is no nuanced question of translation here, the practices of good scholarship, and Nietzsche’s controversial reputation, demand that the text also be examined in its original:
Ich nenne Lüge: etwas nicht sehn wollen, das man sieht, etwas nicht so sehn wollen, wie man es sieht: ob die Lüge vor Zeugen oder ohne Zeugen statthat, kommt nicht in Betracht. Die gewöhnlichste Lüge ist die, mit der man sich selbst belügt; das Belügen andrer ist relativ der Ausnahmefall. – Nun ist dies Nicht-sehn-wollen, was man sieht, dies Nicht-so-sehn-wollen, wie man es sieht, beinahe die erste Bedingung für alle, die Partei sind, in irgendwelchem Sinne: der Parteimensch wird mit Notwendigkeit Lügner.
As the party ages, or ossifies, it attempts to transfer the moral weight of its original focus to its generalized attempt to preserve itself and to preserve and expand its control.
Parties also seek to rewrite history: the desire to sustain power overrides the attraction of intellectual honesty. The Democratic Party in the United States, e.g., does not want to remember that it defended the institutions of slavery and racial segregation.
The lesson for, and from, history is this: there is a significant difference between the principled adherence to an ideology and the unprincipled adherence to a party.