DON’T REPEAT FAILURE AND EXPECT SUCCESS…. When Republican policymakers slashed taxes early in George W. Bush’s first term, they had high hopes about what the policy would achieve. Americans were told, for example, that these tax cuts would create millions of jobs, keep a balanced budget, and generate robust economic growth.

As this tax policy gets ready to expire next month, it’s worth noting that the Republican plan failed rather spectacularly. On job creation, Bush’s record was the worst since the Great Depression. On balancing the budget, Bush racked up the biggest deficits ever, and added $5 trillion to the debt, en route to being labeled “the most fiscally irresponsible president in the history of the republic” by his comptroller general.

But what about economic growth? Did the Republican tax policy generate the robust economy Bush promised? David Leonhardt, responding to a Fox News item, sets the record straight.

Those tax cuts passed in 2001 amid big promises about what they would do for the economy. What followed? The decade with the slowest average annual growth since World War II. Amazingly, that statement is true even if you forget about the Great Recession and simply look at 2001-7. The competition for slowest growth is not even close, either. Growth from 2001 to 2007 averaged 2.39 percent a year (and growth from 2001 through the third quarter of 2010 averaged 1.66 percent). The decade with the second-worst showing for growth was 1971 to 1980 — the dreaded 1970s — but it still had 3.21 percent average growth. The picture does not change if you instead look at five-year periods.

This isn’t a subjective question open to debate; we tried a policy and we can evaluate its results. In this case, Republicans said Bush’s tax policy would produce wonders for the economy, and they got exactly what they wanted. We now know, however, that the policy didn’t generate robust growth, didn’t create millions of new jobs, didn’t spur entrepreneurship and innovation, and certainly didn’t keep a balanced budget.

And now, as the failed tax policy is set to expire, what’s the new Republican message? That this policy must be extended at all costs, and anyone who disagrees is putting the economy at risk.

They not only say this with a straight face, the argument in support of a policy we already know didn’t work manages to scare a whole lot of Dems.