I don't see either progressives or regressives talking about the Armey curve and the Laffer curve. And I don't understand why not, because it's necessary to think of the concepts behind those curves if any conceptual agreement on budgets is to be reached, leaving people to argue about exact numbers.
The concept behind Dick Armey's curve is simple: Zero government spending is a state of anarachy, the war of all against all, and economic growth is impossible. But extremely high government spending kills economic growth. Somewhere in between is a happy optimum that maximizes economic growth, and academic work says that happy optimum is at 33% of USA GDP.
But right now the USA is taxing at only 29.9% of GDP, while spending at 40.8% of GDP to support Bush's wars, so we need both tax increases and spending reductions to hit the 33% optimum. As a separate issue, we're now in a recession emergency where short-term Keynesian stimulus abive the static 33% optimum may be frutful.
Meanwhile the top 0.1% of income earners in the USA are taxed at a rate of only 11%, so they are not pulling their own weight.
Likewise the concept bethind Arthur Laffer's curve is simple, but different: Government can tax at a rate that maximizes its immediate revenues, and that rate is about 45% of GDP, much higher than the Armey optimum.
http://www.truthfulpolitics.com/http:/truthfulpolitics.com/comments/the-... has a discussion of both curves. And a recent article "Sizing the Government" says that the USA should be spending 33% of its GDP on government in order to maximize economic growth. (http://www.springerlink.com/content/mxtp6l2l7w67p505/fulltext.pdf). Data on current government spending is at http://www.usgovernmentspending.com/numbers. Data on taxation versus income is at http://www.newthinktank.com/2011/06/income-in-united-states/.