By comparison, the current top rate is 35 percent, on taxable income above $388,350. If Congress does nothing, the top rate would return to 39.6 percent next year — the same rate that was in place for most of the 1990s.
In dollars, next year's tax hikes would be the biggest. But the population is more than twice as big as it was in the 1940s and the size of the U.S. economy is 80 times bigger. That's why economists usually measure taxes and government spending as a share of the economy.
The 1942 tax increase represented more than 5 percent of the U.S. economy, as measured by the gross domestic product, or GDP. The 1941 tax increase was 2.2 percent of GDP, according to a Treasury Department paper published in 2006.
Next year's looming tax increase would represent 2.6 percent of GDP — a huge tax hike but not the biggest.
Measured another way, the 1942 tax hike increased federal revenue by a whopping 71 percent, according to the Treasury Department paper. The 1941 tax hike increased federal revenue by 32 percent.
By comparison, next year's potential tax hike would increase federal revenues by 16 percent, according to CBO.
ROMNEY: "President Obama has failed to even pass a budget. In February, he put forward a proposal that included the largest tax increase in history, and still left our national debt spiraling out of control, and the House rejected it unanimously," Romney said in an April 4 speech to newspaper executives and editors.
ROMNEY AGAIN: "Rapidly rising federal spending and debt threatens our economic future, and the president has responded by proposing the largest tax increase in history," Romney said in a Feb. 22 release.
THE FACTS: Obama's budget proposal would represent one of the largest tax increases since World War II, if you count letting the payroll tax cut expire as a tax increase. But again, it wouldn't be the largest ever. Obama's 2013 budget proposal mixes tax cuts designed to improve the economy with long-term tax increases aimed at reducing the federal budget deficit.
Obama has proposed extending Bush-era tax cuts for families making less than $250,000 and ending them for families that make more. He would end tax breaks for oil and gas companies but make permanent the research and development tax credit.
In 2013, Obama's budget proposal would increase tax revenue by $195 billion over current policy — if you include the tax increase from letting the payroll tax cut expire. The tax increase would represent 1.2 percent of GDP. Or, measured a different way, it would increase tax revenue by 7 percent.
That would rank as the fourth-largest tax increase since World War II, behind tax hikes enacted in 1950, 1951 and 1968, according to the Treasury Department paper.
Further dousing Romney's claim, House Republicans have passed a budget for next year — which Romney has embraced — that would raise just $7 billion less in taxes than Obama's budget in 2013. That's the equivalent of a rounding error, when you're talking about revenues of $2.7 trillion.
Treasury paper on major tax bills since 1940: http://tinyurl.com/65r8f84
- Here's a quiz to test your Star Wars...
- LA man builds small home for homeless lady
- Britain's new princess can't expect...
- Report highlights earth-shattering increases...
- Defending the Faith: Going up to Jerusalem
- Have you seen 'Age of Ultron'? Here are 50...
- 5 faith facts about Ben Carson: retired...
- 'Avengers' sequel is second biggest US opener...
- Vermont Sen. Bernie Sanders: 'I am... 41
- Rage to relief in Baltimore as 6... 40
- Defending the Faith: Going up to Jerusalem 30
- Former tech executive Carly Fiorina... 17
- Governor, legislators leave 'baggage'... 14
- More Americans spending at least half... 13
- Famed neurosurgeon Ben Carson announces... 11
- Latest on police-custody death: 53... 9