Bruce Bartlett...

...worked on the staffs of Congressmen Ron Paul and Jack Kemp and Senator Roger Jepsen. He was senior policy analyst in the Reagan White House and deputy assistant secretary for economic policy at the Treasury Department during the first Bush administration.

In an interview with the Economist, Bartlett says:

Federal taxes as a share of GDP are at their lowest level in two or more generations—14.9% versus a postwar average of 18.2%. There is not one iota of evidence that the economy is suffering from excessive taxation and no evidence that the sorts of tax cuts favored by Republicans—mainly tax cuts for the wealthy—would do any good given the nature of the economy’s problems. Tax cuts don’t help those with no incomes because they are unemployed, businesses running at a loss, or investors with a large stock of capital losses. In my view, the Republican obsession with taxes is based on pure dogma, not analysis.

That's only a sample. The rest of the interview is worth reading.