Heres how it would work: After the first $1 million in taxable income, the government would impose a 6 percent surcharge on every dollar earned, until it made up for the tax benefits that the rich receive from the low tax rate on that first $45,000. That surcharge remains until the government has clawed back the full $12,420 [the new standard deduction], which would occur at about $1.2 million in taxable income.
They're basically reducing/eliminating the standard deduction on taxpayers who earn more than $1 million.
The impact of this change is likely to be negligible. I suspect most people in this income range are smart enough to figure out how to avoid paying even the 39.6% tax, let along the "effective" 45%.