And the "R" word — as in redistribution of incomes — is being raised by these critics, too, a political killer in any election cycle, but especially in an economic downturn that is squeezing incomes across the board.
The incoming fire isn't just from Republican John McCain, who thinks raising taxes in a sick economy is sort of like the 18th century practice of bleeding. Criticism is coming from the news media and from academia.
"Why raise taxes at all in an economic slowdown? Isn't that going to put a further strain on people?" CNBC economic reporter Maria Bartiromo asked Mr. Obama a few weeks ago. It's a question that could define the rest of the presidential election and boost GOP prospects at a time when the No. 1 issue is the economy, dwarfing the war in Iraq.
Picking up on Mrs. Bartiromo's pointed question, ABC News anchors Charlie Gibson and George Stephanopoulos also pummeled both Democratic candidates last week for their tax policies.
"If the economy is as weak a year from now, as it is today, will you ... persist in your plans to roll back President Bush's tax cuts for wealthier Americans?" Mr. Stephanopoulos asked Mrs. Clinton.
Mrs.Clinton said, yes, she would raise the top 35 percent marginal tax rate on incomes over $250,000 "to the rates they were paying in the 1990s" under President Clinton, which would lift them to a confiscatory 40 percent.
"Even if the economy is weak?" an incredulous Mr. Stephanopoulos asked.
"Yes," she replied without hesitation. "I do not believe it will detrimentally affect the economy by doing that."
But business advocates and economists dispute that claim, saying it isn't just wealthier Americans who pay the top income tax rate, but also 25.8 million small businesses, many of them family-run operations, who create about 75 percent of the jobs, according to the Small Business Administration.
"What Clinton and Obama fail to realize is that small business entrepreneurs also pay that marginal tax rate and raising it will hurt them and by extension hurt the U.S. economy," said economic policy strategist Cesar Conda, who was one of Mitt Romney's campaign advisers.
Sadly, the Democrats' agenda doesn't include small businesses who earn over $250,000 but do not consider themselves rich. Many, in fact, are struggling just to keep their heads above water.
Raising capital gains taxes. Raising the income cap on social security taxes. Raising the marginal income tax rate. This is not the formula for an economic stimulus, but will only increase the likelihood of a recession. Liberals love to say that they are just taxing the rich, but it is always small businesses and the middle class who end up footing the bill through lost jobs and a slowdown in economic growth. "Taxing the rich" is the triumph of ideology over economic sense.