The US/UK didn’t do anything to save Hong Kong’s democracy, so I don’t know how much I’d buy the tired “protecting democracy everywhere” approach. Is it just because we have military bases there?
The US (and post WW2 europe) has a long-standing policy of protecting democratic countries against expansionist dictatorships.
WW2 was an battle between two types of nations: democracies and dictatorships that wished to expand their empires. What is playing out in Ukraine and China is no different. If the democratic world shows weakness (e.g letting Russia to take over Ukraine) it threatens the entire democratic world order since suddenly smaller nations are free pickings to expand Russia / China’s sphere of influence.
Even something as benign as adjusting the temperature for Ukraine related content is 100% in China’s interest here. Ukraine cannot defend itself without the support of the US public, and any sign of weakness from the democratic countries will have material consequences.