Even if China doesn't explicitly align with Russia, I believe there are strategic reasons why the US would want a favourable outcome for Ukraine. I outlined a few points in a post a couple of weeks ago: https://news.ycombinator.com/item?id=42059787

I'm no international relations hawk though, so I'm keen to hear opposing viewpoints.

Trump is pro Trump-looking-strong, and that's about it. Interesting times ahead for sure, but trying to predict Trump's future positions is a mug's game. I suspect regarding Ukraine, someone will give him a plan that they tell him is fair ($10 says Russia keeps Crimea but virtually nowhere else and Ukraine agrees not to join NATO), and he'll manage to get both sides to sign it by threatening them.

The whole Trump/Russia conspiracy theory was all fake anyway - the Steele dossier which is the basis of the whole thing was fabricated and is unsourced. I expect him to be relatively hawkish on Ukraine because losing in Ukraine makes the US look weak, although Ukraine is currently losing the war relatively badly so I expect some territory to be ceded to Russia.

Trump didn’t do anything with regards to China the first time around. I think there’s reason to doubt he is opposed to China in any significant way.

You should probably get it out of your head that Trump supports Russia. Especially considering Russia decided to get frisky with Ukraine in 2014 (during Obama), and 2022(Biden), but took no real action in this regard during the Trump presidency.