Wealth taxes kinda already have been applied to the entire population, except the ultra rich. You pay property taxes, and those definitely go up based on unrealized gains.

Not taking them is a worse precedent. Every year their wealth grows.

Nothing stopping us from voting people in who will raise income tax brackets so only the top 10% pays them.

Nothing but us and our lack of imagination. We can do the same with wealth taxes and the 1%.

Or we can surrender in advance and allow them to continue our March to poverty.

The slippery slope fallacy here does not apply.

It is absolutely a fallacy to say we can't possibly levy a tax on a billionaire lest it, ultimately becomes a tax on us.

Already they have a pretty sweet deal compared to most folks, most folks have most of their 'wealth' taxed as property. Since real property is a tiny sliver of their 'wealth', they get to keep more percentage wise than the random person, despite needing it less.

To say any tax might evolve into a tax on the common man is like saying we can't regulate nuclear weapons, lest it becomes a regulation preventing people from having scissors. Yes, there is the example of income tax and a mistake was made at the time they went to expand it. The problem was not the initial tax, it was the point of expansion. There's no reason the expansion of the tax should have any lower barrier than getting it levied in the first place.

Now if you argue that the measure was somehow flawed in that it failed to limit the scope and explicitly opened the door to things, but it was the opposite, a one-time, billionaire only scoped event.

Income taxes were added to the constitution in 1913 and weren’t limited to only the most wealthy people.

This is why I try to think hard about "temporary" sales taxes and fees and the like. There is about zero chance that tax meets the stated goal and is repealed, if not expanded.