The problem is that, as historian Paul Rahe wrote earlier this year, “we no longer have the resources to support the entitlement state. We can certainly raise taxes, as President Obama and the Democrats intend to do, but that does not mean that in the long run we will take in more revenue — and it is massively increased revenue that the entitlement state needs.” …

That’s just because tax rates are too low, Obama backers reply. Just raise the rates on high earners, and the problem will be solved.

Actually, high earners don’t make enough money to close the current budget deficit. You’d need to raise taxes on middle-income earners too. …

Why is that? As the late Jack Kemp liked to say, when you tax something, you get less of it. When the government took 91 percent of what the law defined as adjusted gross income over a certain amount, not many people had adjusted gross income over that amount.