As Ronald Reagan used to say, the problem in Washington is “that so many people who go there know so many things that aren’t true.”

But maybe it’s not really their fault. After all, plenty of things seem true on the surface. It’s only when you dig into them a bit that you find, well, the truth. Consider “the deficit.”

In 2001 and again in 2003, President Bush cut taxes. In those years the deficit -- which thanks to the “peace dividend” had evaporated at the end of the Clinton administration -- came back with a vengeance. So the tax cuts must have caused the deficit spending, right?

That’s what some experts say. As Isaac Shapiro and Joel Friedman of the Center on Budget and Policy Priorities wrote in 2004, “The Bush tax cuts have contributed to revenues dropping in 2004 to the lowest level as a share of the economy since 1950, and have been a major contributor to the dramatic shift from large projected budget surpluses to projected deficits as far as the eye can see.”

This explanation is admirably simple. It’s also incorrect.

As Heritage Foundation budget expert Brian Riedl explained in a recent paper, the cuts haven’t actually reduced federal income. In fact, they’ve boosted the economy so much that tax revenues have continued to soar.

The problem is that spending has increased even more quickly. And that will be the real problem in the years ahead. “Overall, revenues are projected to increase from 18 percent of GDP to almost 23 percent. Spending is projected to increase from 20 percent of GDP to at least 38 percent,” Riedl notes.

We can’t raise taxes high enough to pay for that additional spending. As Riedl writes, “Even repealing all of the 2001 and 2003 cuts would merely shave the projected budget deficit of 15 percent of GDP by less than 1 percentage point, and that assumes no negative feedback from raising taxes.”

It would be simple to repeal the Bush tax cuts. But that wouldn’t help solve our long-term problem. The answer is more difficult: Lawmakers must lock in the lower tax rates and get spending under control. Small wonder they don’t want to talk much about that. Continued...