Is it reasonable to infer that a wealth tax, if kept modest, could succeed in generating revenue without too much resistance / avoidance from the wealthy, but an intentionally confiscatory tax would probably fail to lessen the power of the wealthy because they would use loopholes, shelters, dodges, political action, and whatever else it takes to defeat the tax or make it toothless?

If we can’t break up the power of the wealthy, we should at the very least stop adding to it.