I think the continual Russian atrocities & war crimes are a reinforcing mechanism for support.
Any moral person knows a bully neighbor lobbing missiles into residential areas, hospitals, shopping malls, etc is wrong. That’s not war, there’s no military objective or benefit. It is simply senseless mass murder.
Watching from afar you know this criminal evil party will not cease their tyranny until they are met by equal and overwhelming force.
The moral question of who to support is simple. Even a child knows this answer.