Media reports in recent weeks say that Senate Democrats are considering a 3% surtax on income over $1 million to raise federal revenues. This would come on top of the higher income tax rates that President Obama has already proposed through the cancellation of the Bush era tax-rate reductions.

If the Democrats' millionaire surtax were to happen—and were added to other tax increases already enacted last year and other leading tax hike ideas on the table this year—this could leave the U.S. with a combined federal and state top tax rate on earnings of 62%. That's more than double the highest federal marginal rate of 28% when President Reagan left office in 1989. Welcome back to the 1970s.

Here's the math behind that depressing calculation. Today's top federal income tax rate is 35%. Almost all Democrats in Washington want to repeal the Bush tax cuts on those who make more than $250,000 and phase out certain deductions, so the effective income tax rate would rise to about 41.5%. The 3% millionaire surtax raises that rate to 44.5%.

Then last year, as part of the down payment for ObamaCare, Congress snuck in an extra 0.9% Medicare surtax on "high-income earners," meaning any individual earning more than $200,000 or couples earning more than $250,000. This brings the total tax rate to 47.9%.