Let's say he earned a million dollars after taxes from his work. And now he puts that money into an investment, and it makes him ANOTHER million dollars. And he's riding high on the hog and he sells and takes his profit of a million dollars. Now he has TWO million dollars...how much is he being taxed on? The only way he is being "doubled taxed" is if he is taxed on $2 million. But he isn't. He is taxed on the GAIN of $1 million. Which is the money he DIDN'T have prior to the investment.
Using your definition of capital gains, he could put the money in a non interest bearing checking account, leave it there for 10 years, and when he pulls it out, get taxed on the withdrawal.
Income is income, regardless of HOW you earned it. Capital gains shouldn't be taxed at any lower rate than Income taxes.
Regardless, the money the US Treasury takes in from him and his 1% exceeds what any other group pays.
You can't handle that?