This won't eat the rich at all. It will only lock out the poor from participating in investments. An unrealized gains tax is effectively a prepayment on your eventual realized gains.

It'll make stock investments unattainable for the cash poor. If you're taxed on unrealized gains you have to pay tax on earnings you haven't actually earned (and may never actually earn). The cash poor will not be able to pay this tax and therefore cannot invest. The rich can pay it as they have liquid cash on the sidelines. 

Taxing unrealized gains ultimately becomes a timing issue. Once a security is realized, you end up at the same net amount of tax paid (you pay more upfront and less upon disposition). A tax on unrealized gains is effectively a prepayment on your realized gains. The rich who can afford to prepay will not pay any additional taxes net. This will not eat the rich but simply lock out the poor.

This gets crazier because if the unrealized gain turns into unrealized loss later down the line, how is that handled? Is the government going to provide a rebate/return on the difference? Tax basis is already a nightmare to deal with as-is, this is just another massive layer of complication to add on top. Just on data volume alone, this will likely add, on avg 5-10x more transactions to process. And thats not taking into consideration the significantly more complicated rules/exceptions that will need to be put in place and the level of additional rollforward tracking required for the lifetime of every position. This will become an absolute logistical nightmare from a tax accounting perspective. 

 So, basically, bullshit  

 Absolutely. It's added complication for no real gain for anyone.

The rich get taxed the same. The poor get priced out. The accountants have to work more for the same cost. The government arguably gets less tax money because it will reduce total investments in the market.

Literally no one gains from this. 

 Scamala Harris 😂😂