As the chart shows, Obama’s give-and-take tax policy results in marginal tax rates of 34 percent to 39 percent in the $31,000 to $45,000 income range for this family. That’s an increase of 13 percentage points or more from the current rates.

What accounts for the higher rates? First, Obama expands the maximum child and dependent care credit for families with one young child from $1,050 to $1,500 and phases down the credit over a longer income range, from $30,000 to $58,000. Throughout this income range, the credit is phasing out at a rate of $30 per $1,000 of income, thus raising the effective tax rate by 3 percentage points. Obama also makes certain credits refundable, which introduces a tax penalty of 10 percent or 15 percent, depending on the income bracket.

While Obama has publicly embraced a tax rate of 40 percent for couples earning over $350,000, his tax policies would result in a staggering 45 percent effective marginal rate in the $110,000 to $120,000 income range for this family. That is 11 percentage points higher than under current law.

The culprit in this case is Obama’s proposed reform of the Hope Scholarship Tax Credit for college tuition, which he would rename the “American Opportunity Tax Credit.” He would increase the credit’s maximum value from $1,800 to $4,000 while still phasing out the credit over the same income range, $100,000 to $120,000. The larger phase-out would boost the penalty on work from 9 percentage points to 20 percentage points.

Although Senator John McCain would not eliminate the existing phase-outs, he would avoid adding new ones, with one small and temporary exception. While McCain has proposed increasing the personal exemption for children, he would make it immediately available only to lower-income taxpayers. Until the bigger exemption is offered to everyone in 2016, some households would face an additional effective marginal tax rate of about 2 percentage points.