There is exactly one measure which will actually get the rich to pay more in taxes: combine (a slight) lowering of the top marginal rate with a cap on the amount of income which can be excluded from taxation by any combination of deductions, tax-exempt sourcing, and credits (the last with the credit counting as excluding an amount of income equal to the amount of the credit divided by the tax-payer’s top marginal rate). Replacing the AMT with such a scheme would also make filing taxes easier — the form would be about six lines long instead of the two page AMT form an awful lot of us have to fill out annually, even if we don’t end up owing AMT. (I have to file the blasted thing every year, and only once had to pay AMT, in a year when I had extra income from a sabbatical appointment).
This is also the only measure I can conceive of which is simultaneously a boon to capital formation and a “soak the rich” plan. (The lowering of the top marginal rate is to ensure that the broadening of the tax base at the top end doesn’t encourage capital flight to other countries with lower marginal rates.)
Taking 100 percent of the wealth would not satisfy the left. They’re greedy, self-absorbed, mean-spirited, intolerant, and completely lacking in basic human compassion.