Hard to not see how ideology plays into it. Russia portrays itself as a traditional, conservative, religious state with a strong (white, male) leader - something that appeals to a lot of the GOP. China is obviously communist (at least in name if not always in practice) and not a European power. That's not to say there aren't some elements of China that Republicans don't admire, just that it's practically custom-built to be a conservative boogeyman in a way that Russia hasn't been since the days of the Cold War.
The interesting thing (to me, at least) is how this really isn't reflected across the aisle. Basically every remotely mainstream Democrat dislikes both Russia and China on "they're authoritarian" grounds pretty equally. Maybe Russia has overtaken China as the biggest bully since the Ukraine invasion, but even now, you'd be hard-pressed to find a Biden voter who speaks positively of the Chinese government. Are there people on the left who like Xi? Sure. But do they have anywhere near the level of influence as people on the right who like Putin? Absolutely not. And that's not me trying to get a jab in against Republicans (well, maybe a bit), but more just to ask why that is, when there's really no structural reason in the differences between the parties why one would be more inclined to look at foreign adversaries through a more ideological lens than the other.
The intellectually lazy TL;DR of this is racism and white supremacy. Jabs at low-effort soundbite talking points aside, I would strongly argue that anti-China sentiment across the aisle would still be very much a thing even if the country remained (nominally) KMT-controlled.
