I didn't completely grasp this for a very long time despite understanding 'American Liberals' were not the same as 'Classical Liberals' - it's not intuitive.

To prevent confusion the etymology is the same as the word "Christian". Both Catholics and Protestants are Christians. Sometimes one will claim to be more 'Christian' than the other but that is beside the point: to a non-Westerner they're the same group. The same is true of the word "Liberal". Democrat Liberals, Progressives, Conservatives, Republicans, Libertarians - these are all species of Liberal.

What this means may be found controversial by some people.

This would mean in the West, or at least in the Anglosphere political authority is typically wielded by two competing variants of the same political philosophy.

I find this interesting because that is not at all what is advertised.

For years I thought the differences between China's One Party State and the West were plain to see but now I think the distinction is less obvious. Going back to my Christianity analogy, it may be an argument over The Holy Trinity - both completely different and also the same simultaneously.

Is the West a Two Party System with one faction? Is China a One Party System with multiple factions? If so what's the real difference or is there a real difference?

There's a strange perspective distortion where the differences are either enormous or minor but it's hard to tell which - I speculate that metapolitics has a Lovecraftian quality to it where it might not be possible to understand without going insane. :)