There is always a party line. The only question is whether or not it is any good.
I.e., the only question is whether or not it is true.
Most party lines are somewhat mistaken, so somewhat false; for, we see now as if through a clouded glass, and but darkly.
There are then two tests of a party line. The first is logical. Is it consistent and coherent? Does it refute itself? Does one of its propositions contradict another? If so, it is false; for the world is both coherent and consistent (this being the only way to obtain any world, properly so called).
The second test is practical. Does it work? In other words: no matter how beautiful and therefore alluring it is, no matter how consistent and coherent it is, does it actually work out in practice? If not, it might pertain to some other world, but not to ours.
The first test is of possibility. An incoherent or inconsistent party line can’t work in any possible world. It is not logically coherent, and cannot therefore be enacted, by anyone, in any cosmos.
The second test is of compossibility. A coherent consistent party line must be workable and potentially successful in this our own world.
If a line has passed the first test, then and only then has it any shot at passing the second.
Most party lines of the modern age fail both tests.
Most traditional party lines pass both. They must have, or they could never have survived long enough to become traditional.
Res ipsa loquitur.
PS: As there is always a party line, so is there also always a party: a nomenklatura – a class of namers – who by their acts and especially their public utterances shape the narrative by which every society describes itself to itself, and who determine what society may and may not notice in support of that narrative.