The total income from tax increases is relative to the gross income. The gross income of the 1th percentile of earners in the US is ~$3.3 trillion, whereas the gross income of the top 25% is ~$10.3 Trillion. Levying a tax against only the top 25% sans the top 1% would yield more taxes than the inverse. Small increases on large brackets tend to generate significantly more tax revenue than large increases to small brackets.