A Pretty Good Question

I read Arthur Laffer's essay in the Wall Street Journal where he predicts that because humans are rational, they are going to kill the economy next year when the Bush tax cuts are eliminated. Laffer shows that growth was limited for the first two years of Reagan's Presidency because Reagan agreed to delaying the effect of the tax cuts until 1983.  It's at that time that read GDP took off.

Although many on the Left complained that this was the start of massive deficits, they are only partially correct, in that revenue did go up when the tax cuts were implemented.  It's just that spending went up even faster.  If spending would have held steady in the Reagan years, there would have been a surplus, but that fact is always lost on those who see Reagan as the incarnation of the Anti-Christ.
We are now in a position where we are spending even more than GW Bush spent.  In fact, Obama is something like three times the spending per day that Bush had spent, and there is little that seems to be done about the problem, except to create a commission to study the problem.  Of course, the first thing the commission does is to declare that they need more funding.
So, it seems inevitable that there will be tax increases.  As I have always said, the idea that the rich aren't paying their fair share of taxes means that people should demand a rate cut for the wealthiest individuals.  As noted in this article:

The results of such a system can be plainly seen in the U.S. tax system. According to Congress’ official and nonpartisan tax estimator, the Joint Committee on Taxation, the top 3.7% of filers earn 27.1% of the nation’s income. Yet they pay 54.8% of the total income taxes—more than double their income share. In contrast, the bottom two-fifths of earners (39.9%) earn 7.7% of the income and pay negative 2.1% of the income tax (due to government spending in the form of refundable credits).

Our tax code is a mess.  We pretend to make it fair by calling it progressive, when the only thing progressive is the rate of confiscation at higher levels.  Which leads me to the question in the title.  At what rate does an increase in the "progressive tax rate" become unfair?  According to Obama, there is a point at which you can supposedly earn too much.
So, what exactly is that point, and why?