loquitur

That's simply not true. Tax rates were nominally more progressive, but the actual rates paid at the top were not very much different from what they are now, because the tax code was riddled with exemptions, shelters and other such things. That in itself created unproductive activity (tax-saving-oriented planning and investment instead of productive planning and investment), which means that the economy likely would have been even better with a sane tax structure. But you're confusing nominal rates with actual rates, and the two have only a tenuous relationship to one another. The fact is that taxes actually paid are more progressive today than they have ever been in history. The bottom half of the income scale pays something like 3% of the income taxes. The top 1% pays something like 40%. I believe the top 5% pays something like 70%. You claim not to want to cap or confiscate, but how much more progressive do you think you can make the tax system than it is right now? You can make it saner and simpler but it can't get very much more progressive. The tax system has many things wrong with it, but lack of progressivity isn't one of them.