Taxing unrealized capital gains is incredibly harsh. Basically cuts your yearly returns in half, and that completely destroys your returns over long periods of time (30 years). Out of all the proposals, this seems the most insidious.

Taxing unrealized capital gains (provided you also allow deduction of unrealized losses) is equivalent to taxing net realized gains except in effect on the power people holding large unrealized gains can exercise over society. It doesn't have any effect on net, after taxes returns.

I'm not sure I follow. Let's assume 10% growth of your assets every year, with 50% tax on gains. You start with $1k. After 30 years you liquidate all assets.

If taxing unrealized gains, you end up with $1k * (1.05)^30 = 4,321 If not taxing unrealized gains, you end up with $1k * 1.1^30 = $17,449 and then pay 50% tax on $16,449 when you liquidate, so you end up with $9,224.