Of all the arguments that have been made in favor of extending the Bush administration tax cuts on the wealthiest Americans and not letting them expire on New Year’s Eve, the most potent one goes something like this: If you raise taxes on people earning more than $250,000 a year, you will hurt large numbers of small-businesses.

Senate Republican leader Mitch McConnell, in pushing for retention of the tax cuts on wealthiest Americans, has argued that the top-two tax brackets “cover 50 percent of small-business income” as well as “25 percent of the workforce.” He said on the Senate floor: "We can't let the people who've been hit hardest by this recession and who we need to create the jobs that will get us out of it foot the bill for the Democrats' two-year adventure in expanded government."

The U.S. Chamber of Commerce and Eric Cantor, the House Republican leader-elect, agree, as do large numbers of the resurgent Republicans on Capitol Hill.

Since making those remarks, of course, the Republicans’ power in both houses of Congress has increased, making it even more likely that tax cuts for the wealthiest of Americans are going to be extended—ostensibly for the benefit of small business. President Barack Obama's administration is expected to meet with Congressional leaders today to discuss the tax-cut-extension issue.

Interestingly, what we’re seeing now is some pushback from an unaccustomed source—an impressive number of small-business people who have signed on to a petition opposing extension of the tax cuts for wealthy Americans—essentially turning the Republican arguments on their head. They’ve organized a group called BusinessForSharedProsperity.org. A list of signatories can be found here.

This may seem at first blush like a bunch of pinko small-business operators infiltrating the holy precincts of capitalism, but that’s not exactly so. Shortly before Thanksgiving, Warren Buffett firmly rejected the notion that the super-wealthy should pay less in taxes. He said “that people at the high end—people like myself—should be paying a lot more in taxes. We have it better than we've ever had it.”

Significantly, Buffett also rejected Republican arguments that cutting taxes on the wealthiest will hurt economic growth. Said Buffett: "The rich are always going to say that, you know, just give us more money, and we'll go out and spend more and then it will all trickle down to the rest of you. But that has not worked the last 10 years, and I hope the American public is catching on."

The “trickle down” reference harkens back to the supply-side economics doctrines of the Reagan administration, which maintained cutting taxes on the rich was a sure path to prosperity for everyone. That’s an article of faith for Republicans, but is discounted by most Democrats.

The business people who favor letting the tax cuts expire have produced a new study backing up their position that cutting taxes for the wealthy is really bad for business. The principle arguments are these:

Small-business hiring is driven by consumer demand, not tax rates. The logic here is that tax rates simply don’t figure in to business-hiring decisions. If the demand is there from consumers, the jobs will be created, whatever the tax rates may happen to be.

Job growth was better before the Bush tax cuts. This argument is a corollary of the last one and is based on job-growth data from when the tax cuts were implemented in 2001. This argument maintains that the 2001-2007 economic expansion was weaker, in terms of job creation, than any previous expansion, and that the Clinton years showed considerably more jobs created, with higher tax rates. Indeed, they point out that rates would be returned to what they were during the strongest economic expansion in history.

Few small-business owners would be affected. One of the most potent arguments by opponents of continuing the tax cuts for the wealthiest Americans is a head-on rebuttal of McConnell’s argument that large amounts of small-biz “income” would be affected. Measured another way—by the number of small-business operators—the numbers are, they say, much smaller. They maintain that less than 3 percent of people with small-business income are in the highest bracket. (A study by American City Business Journals, Portfolio.com's parent, says that if sole proprietors and other very tiny businesses are removed from the equation, the percentage is much higher. A full analysis can be found here.)

To me, the clincher argument is this one: If “trickle-down” is still a viable argument, where is all that Wall Street income? If it’s been “trickling” all this time, why are we still mired in economic doldrums? What about all those billions and billions of dollars accrued by financial-company executives, hedge fund managers, and the like? In fact, the study notes, the 400 richest taxpayers “increased their average income by 399 percent, adjusted for inflation, between 1992 and 2007”—and lowered their effective income tax rate—thereby widening the already serious problem of income inequality. That’s the open sore of the “plutonomy”—the rich getting richer while everyone else eats mud—that I’ve explored in this space in the past.

To be realistic, it’s hard to believe that arguments like this are going to carry the day. The political winds are just too strong—and they’re blowing in the direction of giving the rich the windfall that won’t do the economy the slightest bit of good. You can’t say Congress hasn’t been warned, and by the same small-business people that supposedly are going to benefit from extension of the tax cuts.