So I don't think Elon is anti-Ukraine. He's just another armchair "expert" spooked by the big numbers thrown around regarding Russia's military. He like others simply fails to realize those numbers don't matter, what matters is what they have the capacity to field and Russia can only effectively field a small fraction of their theoretical strength. Truth of the matter is, what they have fielded is probably near the max they can field effectively. They just do not have the economic, industrial, or logistical capacity to field anywhere near their full theoretical strength. Now they've had time to build up infrastructure in occupied regions to bulster that, but Ukraine is doing a lot of damage there so it likely won't matter much longer in most of the occupied regions.
But that aside, fact is the possibility of Russia getting major concessions from Ukraine died months ago. They probably could have gotten a fair bit in March or April when Ukraine was still on the backfoot and international support was still forming. But now? Not only has Ukraine's victories emboldened their people and Russia's conduct enraged them, Russia's losses and dysfuction have severely damaged their reputation as a major power and power broker. Add on that that no one trusts Russia and that outcome becomes a clear political impossibility.
But Elon is right about one thing: for this to end, both sides will likely have to back down from their maximalist demands. Russia has no chance of fully controlling through regime change or occupation all of Ukraine. They have recognized this and scaled back, but even their new goals are proving a stretch. For Ukraine, it's lovely to dream of deposing Putin, trying half the miltary bureaucracy for War Crimes, demilitarizing Russia, and confiscating their nuclear arsenal, but that's just not realistic. No nation has been compelled to accept a treaty so harsh in nearly 80 years. And that only happened at the literal barrel of a gun, with Germany and Japan thoroughly defeated and facing eminent total defeat and occupation anyway. Ukraine doesn't have the capacity to do that to Russia, even with western assistance. The only way that has a chance of happening is if Russia implodes from within. Which isn't impossible, the Soviet Union collapsed afterall. And the provisional government of the Russia also collapsed in WWI, largely due to colossal military failures. But that is a long shot.
So there's unlikely to be a nice, clean, "good guys win" end to this. There will be negotiations at some point, the fighting leading up to that will all be about leverage.
On a side note regardin the US support, as of now it is broadly bipartisan and enjoys significant majority support. If things continue as they are, I don't see that changing regardless of the party alignment unless something really wacky happens with the fringe wierdos becoming way more popular nationwide. The two biggest threats aren't the parties or anything like that. It's inflation and feelings regarding NATO contributions. Inflation is one of the very few things that tends to make people sit up and take economic policy and spending seriously for a change. It also tends to turn national concern inward. So support for Ukraine could become collateral damage if inflation is still running hot in 2024. The NATO issue is more about NATO members following through on defense spending. The "free rider" argument that the US does all the defense spending heavy lifting was a common talking point for years. If 2024 rolls around and NATO nations have pumped the breaks on defense spending increases, I could see this creeping back into the discourse despite the unifying effects of the Ukraine conflict. A lot of Americans came to feel over time that NATO leaned too much on the US to be the muscle (somewhat fairly, though the US is the one that chooses to spend so much on defense) and could become antsy if they feel the Ukraine conflict is becoming a predominantly US responsibility.
But honestly that second bit I don't think will be as impactful as the first one. Unless other NATO countries actually do seriously mess up. Again, so long as things progess mostly positively.
But we'll see. Honestly, Russia needs to make it to 2024 first.