Correlation is not causation. Economics is diabolically difficult to figure out. If you assume that the government does not waste too much money (including buying votes), and that actually helps the economy in the long run, you would argue that "big government" is a good thing, and use Clinton (even though he said the era of big gov is over) as evidence that raising taxes does not necessarily hurt the economy.
Although GWB was a failure, I think the Obama presidency has been much worse. Although I can understand voting for neither Romney nor Obama, I can't imagine voting for such scum as the latter. I am ashamed of the people who voted for him.
Here’s the study:
(it was the Congressional Research Service not the CBO so sorry for misstating that it was put out by the CBO)
If you read through and look at the statistical analysis there is no statistically significant link between marginal tax rates and GDP. If anything GDP growth has been slowing since we started lowering marginal tax rates but again it’s not statistically significant.
But there is a significant link between marginal rates and the concentration of wealth at the top.
What needs to be argued is if concentration of wealth is harmful to the economy or not.