You're saying revenues have NOT dropped in France, the UK, and California following tax hikes on the rich? Sorry pal, the truth may not fit your agenda, but that's EXACTLY what happened. Google it yourself. George Bush I learned the same lesson when he increased taxes in 1990. In 1989, federal revenues were 19.3% of GDP. In 1991, after the tax rate hikes, revenues slipped to 19.1%. According to the WSJ, the rich in particular paid LESS taxes after the rates where raised - $6.5 billion less! The WSJ report stated "81% of the revenues expected from the 1990 budget deal failed to materialize". There are plenty of other examples if you care to look with an open mind.
Revenues depend on two things: tax rates and the state of the economy. If the economy is depressed, the revenues are low.
Correct, if the economy is depressed, revenues go down. That's the point. History shows us (in America, in states, and in other countries) that there is a causal relationship between raising tax rates and a slowing of economic growth and therefore, tax revenues.
Depression, however is always temporary. So the higher tax rates will bring more revenues eventually.
We are not in an economic depression by anyone's measure, but that's beside the point.
What is on point is that higher tax rates often do not bring in more revenue, especially when those rates are increased on wealthy people who have the choice with regard to how they spend or invest and even how of if they take an income.
I'm afraid history does not support your assumption that higher rates will bring in more revenue. Not now, not ever. This is why the total tax revenues to GDP stay about the same regardless of the overall tax rates. It's also why you're correct that the best way to increase revenues is to grow the economy. The worst thing to do to grow the economy is to tax more those that are often the source of capital, investments, and big ticket spending (the rich). The best thing you can do to grow the economy is to keep taxes as low as possible.
There is just way too much evidence of increasing rates rates resulting in less tax revenue and a suppressed economy. There is also much evidence that decreasing tax rates results in a better economy and yes, more tax revenue. That was certainly the case after Clinton lowered the Capital Gains rate in '94. Tax revenues skyrocketed as the economy boomed. There are many other examples as well.
Bottom line, if you really want to get more money out of rich people, lower their tax rates, embrace free market measures, and the economy, right along with tax revenues, will grow.