Riding a wave of confidence after his re-election victory, President Obama is eager to collect scalps from the class war he appears to have won. Americans, Obama said in his postelection news conference earlier this month, "want to make sure that middle-class folks aren't bearing the entire burden and sacrifice when it comes to some of these big challenges. They expect that folks at the top are doing their fair share as well." House Minority Leader Nancy Pelosi, D-Calif., echoed this point in a fundraising pitch sent out on Monday: "Voters sent a clear message to Republicans in the election: we must stand up for the middle class and ensure the wealthy pay their fair share."

Although Obama and his fellow Democrats repeatedly call on wealthier Americans to pay their "fair share," they never specify what percentage of the nation's tax burden the wealthy would have to bear. As matters stand, the top 1 percent of American households paid 39 percent of income taxes in 2009, according to the most recent data compiled by the Congressional Budget Office, and the top 5 percent of taxpayers paid 64 percent.

But income taxes, taken in isolation, do not tell the whole story, because lower-income Americans do pay payroll taxes. But even taking into account all forms of taxation, the top 1 percent still paid 22 percent of federal taxes while earning just 13.4 percent of household income. The top 5 percent paid 40 percent of all federal taxes, despite earning only 26 percent of all income. No matter how you slice the numbers, it's hard to understand why anyone would think the wealthy aren't already shouldering a burden commensurate with their blessings.

In the next few weeks, Obama will keep repeating this "fair share" language as part of his call to raise taxes on those earning more than $250,000 per year. He also wants to close additional loopholes and limit deductions to increase their tax burden further. But bear this in mind: On top of whatever new taxes go into effect in the deal to avert the so-called fiscal cliff, there will be additional new taxes due to Obama's national health care law. These include a 0.9 percent Medicare tax hike for individuals earning more than $200,000 per year and couples earning more than $250,000 as well as a 3.8 percent surtax on investment income.

Moreover, even if Obama gets his way on all of his tax hikes on the wealthy, it still won't make a dent in the $16.3 trillion national debt. Later in his term, once he has blown all of the new revenue with spending increases and goes back to this well for still more revenues, will the media let Obama get away with claiming the wealthy aren't paying their "fair share" once again, without specifying what constitutes fairness?