Unconstitutional.
Presidents do not have the power to tax. He can urge the House to initiate his tax ideas but it must pass the Senate first. More taxes in a election year will not help Democrats unless they think voters in general hate the rich as much as they do.
FTA: ...but also their unrealized gains on stock holdings and other forms of wealth...
Gov’t: Looks like you are going to make a million. Gimmee!
Taxpayer victim: I have not made any money yet. It is being invested to help that company grow and make money. They will hire more people. Once the stock price goes up and IF I sell then I will make money that can be taxed.
Gov’t: Nope, we want made up money that we can tax that we determine the amount of.
Taxpayer victim: I will then not invest and the company will lose and the employees will be let go and no money will be made.
Gov’t: Not our problem. We can always print money.