The NYT points out that even a hike of a few percent on the ultra-rich could yield massive returns. For instance:
If the tax increase were limited to just the 115,000 households in the top 0.1 percent, with an average income of $9.4 million, a 40 percent tax rate would produce $55 billion in extra revenue in its first year.
That would more than cover, for example, the estimated $47 billion cost of eliminating undergraduate tuition at all the country’s four-year public colleges and universities . . . .
The article also notes that "most mainstream economists" agree that cutting taxes would leave a budget gap rather than paying for itself.
Finally, the article is worth a read for its informative chart breaking down incomes and taxes by income quintile as well as a further breakdown of the top quintile to show how dramatically the top incomes dwarf the rest.
Check it out, here.