What if you make $10,000,000? The person in the $250k+ bracket has a higher opportunity cost than the person making 40x that. IMHO $250k is upper middle class, and in no way should be considered rich. The pundits for progressive taxation always seem to forget that the highest tax bracket is not in the millions.
So while my example shows it would be positive for the person making slightly more than the bracket, making even $10k more creates a negative situation.
You do realize that progressive taxation only applies to income over the tax bracket.
For example, if a married couple earns 275,000 dollars a year under Obama's plan to return the top bracket to Clinton era levels:
Their first 15,650 dollars is taxed at 10% - just like someone earning just 10k a year.
Their income between 15k and 63k is taxed at 15% - just like someone earning 60k
Their income between 63k and 128k is taxed at 25% - just like someone earning 120k a year.
Their income between 128k and 195k is taxed at 28% - just like someone earning 190k a year.
Their income between 195k and 250k is taxed at 33% - just like someone earning 240k a year.
Then only their income between 250k and 275k is taxed at the new rate of 39%.
A lot of people that are against progressive taxation don't even know how it works. They think that as soon as one gets into a higher bracket that all their income is taxed at the higher rate.
Moreover, after deductions (kids, interest, state and local taxes, and so on), most households would have to earn well over 250k a year for any of their income to end up being taxed at the 39% rate.
Its a myth that a raise can reduce your net income if it puts you in a higher bracket. The only conceivable way that could happen is if you fell under the AMT. In my life I have jumped through a few income brackets as I went up the career later and none of those increases in gross income ever resulted in a net reduction of income after taxes.