Back in 1955, when the US had a 91% top marginal tax rate, per capita revenue from the income tax was $2595 in 2008 dollars. In 2010, in the midst of economic torpor? $4418. Why was $2595 sufficient to run the country back in the mid-1950s - a time period described by Paul Krugman as an economic and political "paradise lost" - but yet $1500 more than that today is regarded as evidence that taxes must be raised? In fact, the US is currently collecting more per capita income tax revenue today that every year prior to 1987.
Andrew's fantastic response centers on the fact that, since 1955, we've had Medicare and have maintained military expenditures at Cold War levels when we have no credible military threat against us. Underneath that, Americans are far older on average than they were then, which means the government has to spend more for their care and well-being. Republicans don't have a plan to deal with this; they just want to cut spending on entitlements and leave every person to fend for himself in an increasingly cutthroat economy. That approach isn't without some merit, of course. I agree that Medicare needs to be means-tested, and I think the official retirement age needs to be increased over time. We are living far longer than we ever have, and our bodies are lasting longer. The time when we could expect a robust retirement of 10 years or so has now turned into 20+ years, and the benefits from Social Security don't keep up. Simple matter of supply and demand.
But this reader -- you just know this turkey watches Fox News and goes to Tea Party rallies. I'm surprised the reader's post didn't feature complaints about illegal immigration, foreign aid, and the welfare state. Just proves that there's no such thing today as an intelligent Republican.