If you listen carefully you can start to hear a pattern of voices on the center-right making an economy-related argument against tax increases. Bloomberg News has an article reporting on a comment by a House Republican leader, Mike Pence: "Raising taxes during the worst economy in 25 years is a profoundly bad idea and I won't support it." Over at the Financial Times, Clive Crook writes, "On the immediate issue, a simple compromise presents itself. As Harvard University's Martin Feldstein has proposed, extend all the tax cuts for two more years, allowing the recovery to gain momentum; then reverse all of them, to help bring public borrowing back under control."
This is a timely argument given the jobless rate and the sense that economic growth is slow, so it's hard to fault Mr. Pence for making it. But, as the Crook/Feldstein position demonstrates, the flip side of opposing tax increases in an economic downturn is favoring tax increases in an economic upturn. So this is an argument to be careful about.
The strongest case against tax increases is a case that is not dependent on what the state of the economy happens to be at one time or another but involves the timeless concept that an individual has a moral right to his own property, including the product of his own labor. Another strong argument is that individuals are better at allocating resources than government is.
The idea that the government can assess economic conditions and then fine-tune the operations of the economy via adjusting the tax rates just enough so that they don't hurt growth too much requires a kind of faith in central planning that runs against some of the logic of tax cuts in the first place. I realize the traditional view is that there is fiscal policy and monetary policy, and that fiscal policy includes both taxing and spending. If fiscal policy is to be used to fine-tune the economy, I'd prefer tax cuts to spending. But the whole exercise cedes a lot of ground to Keynesianism. If the argument is just over what the optimal tax rate is for growing the economy as a whole, it's an empirical question. But even if, just hypothetically, the answer is that the best tax rate for overall growth were 70% on the top brackets, it doesn't answer the moral question of why the good of the overall economy trumps the property rights of the person who is having 70% of what he earned taken away from him.