Republicans are entitled to their own opinions, but they're not entitled to their own separate reality.  When Republican Sen. Jon Kyl said on Fox News that tax cuts had no impact on the deficit, that was bad enough. But Senate Minority Leader Mitch McConnell grabs the wacko baton and sprints ahead when he tells TPMDC's Brian Beutler that "there's no evidence whatsoever that the Bush tax cuts actually diminished revenue. They increased revenue because of the vibrancy of these tax cuts in the economy."

Sen. McConnell might not believe the evidence provided by the Congressional Budget Office, the Committee for a Responsible Federal Budget, the Joint Tax Committee, or the Brookings Institution, all of which concludes that the Bush tax cuts added to the deficit.

But surely he should believe President George W. Bush's own Ph.D-wielding economists. Many of them have gone on the record to say that while they supported the tax cuts, they didn't for one second believe they raised government revenue.

1) The Council of Economic Advisers' Report to the President, 2003: "Although the economy grows in response to tax reductions (because of higher consumption in the short run and improved incentives in the long run), it is unlikely to grow so much that lost tax revenue is completely recovered by the higher level of economic activity."

2) The chair of CEA from 2003-2005, Greg Mankiw: "Some supply-siders like to claim that the distortionary effect of taxes is so large that increasing tax rates reduces tax revenue. Like most economists, I don't find that conclusion credible for most tax hikes, and I doubt Mr. Paulson does either."

3) He's right! Hank Paulson, Bush's last Treasury Secretary, doesn't: "As a general rule, I don't believe that tax cuts pay for themselves."

4) That opinion was shared by Andrew Samwick, Chief Economist on Council of Economic Advisers, 2003-2004: "No thoughtful person believes that this possible offset [the Bush tax cuts] more than compensated for the first effect for these tax cuts. Not a single one."...

5) ... and Edward Lazear, chair of the Council of Economic Advisers in 2007: "I certainly would not claim that tax cuts pay for themselves."