It's easy to imagine it, but it's also easy to imagine a beautiful woman riding a unicorn to come give me a bj no questions asked. Look what happened during the health care debate. Maybe you weren't watching that closely from NZ, but there were angry mobs threatening Congressman who were trying to hold town halls. The monied interests exploited that to the fullest extent they could ("Keep your government hands off my Medicare", for example). That was for something that was proposed to be paid for by a modest sur-tax. What wouldn't they do if all of a sudden someone said, "We're going to tax 30% of your wealth, so if you don't have the cash, you better liquidate quick." They would pull out all the stops. Not to sound like a conspiracy theorist (I'm not), but I would bet dollars to doughnuts that the Kochs et al. already have a playbook lined up for just such a case.. They read the news. They know what economists are saying and proposing....it's easy to imagine it without chaos.
Your system is broken beyond repair if you really can't discuss returning to tax rates of (say) 30 years ago without invoking chaos. The business interests have won and it's game over. And by the way, I wasn't even talking about that, I was talking about raising the minimum wage, which is not a tax at all (but it is a gov't mandated increase in business costs, so effectively pretty similar to raising taxes - on some businesses).