A long time ago, the top marginal rate in the U.S. topped out at 90 percent, if I'm not mistaken.
Would anybody be in favor of even a temporary 75 percent tax rate for the super rich like the one being pushed in France? I suspect not. Such a move isn't even necessary and would only further gum up an already crazy tax system.
I wouldn't be in favor of such a tax height, though I am in favor of allowing the Bush-era tax cuts to expire at the end of this year, which would push the top marginal rate back up to 39.6 percent and push us a long, long way down the road to fiscal sanity.